8 Management of Waste



8.B.1 In-Laboratory Hazard Reduction

8.B.2 Characterization of Waste

8.B.2.1 Characterization for Off-Site Management

8.B.2.2 Identification Responsibilities of All Laboratory Personnel

8.B.2.3 Characterization of Unknowns

8.B.2.4 In-Laboratory Test Procedures for Unknowns

8.B.3 Regulated Chemical Hazardous Waste

8.B.3.1 Definition of Characteristic Waste

8.B.3.2 Definition of Listed Waste

8.B.3.3 Determining the Regulatory Status of a Waste

8.B.3.4 Empty Containers

8.B.4 Collection and Storage of Waste

8.B.4.1 Accumulation of Waste at the Location of Generation

8.B.4.2 Accumulation of Waste in a Central Area

8.B.4.3 Special Regulations for Laboratories at Academic Institutions

8.B.5 Disposal of Nonhazardous and Nonregulated Waste

8.B.6 Treatment and Disposal Options

8.B.6.1 Treatment and Recycling

8.B.6.2 Disposal in the Sanitary Sewer

8.B.6.3 Release to the Atmosphere

8.B.6.4 Incineration

8.B.7 Monitoring Waste Services, Transport, and Off-Site Treatment and Disposal

8.B.7.1 Preparation for Off-Site Treatment or Disposal of Waste

8.B.7.2 Choice of Transporter and Disposal Facility

8.B.8 Liability Concerns

8.B.9 Manifesting Hazardous Wastes

8.B.10 Records and Record Keeping


8.C.1 Chemical–Radioactive (Mixed) Waste

8.C.1.1 Minimization of Mixed Waste

8.C.1.2 Safe Storage of Mixed Waste

8.C.1.3 Hazard Reduction of Mixed Waste

8.C.1.4 Commercial Disposal Services for Mixed Waste

8.C.2 Chemical–Biological Waste

8.C.2.1 Disposal of Chemically Contaminated Animal Tissue

8.C.2.2 Sewer Disposal of Chemical–Biological Liquids

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8 Management of Waste 8.A INTRODUCTION 185 8.B CHEMICAL HAZARDOUS WASTE 186 8.B.1 In-Laboratory Hazard Reduction 186 8.B.2 Characterization of Waste 186 8.B.2.1 Characterization for Off-Site Management 186 8.B.2.2 Identification Responsibilities of All Laboratory Personnel 187 8.B.2.3 Characterization of Unknowns 187 8.B.2.4 In-Laboratory Test Procedures for Unknowns 187 8.B.3 Regulated Chemical Hazardous Waste 189 8.B.3.1 Definition of Characteristic Waste 189 8.B.3.2 Definition of Listed Waste 190 8.B.3.3 Determining the Regulatory Status of a Waste 190 8.B.3.4 Empty Containers 191 8.B.4 Collection and Storage of Waste 191 8.B.4.1 Accumulation of Waste at the Location of Generation 191 8.B.4.2 Accumulation of Waste in a Central Area 192 8.B.4.3 Special Regulations for Laboratories at Academic Institutions 194 8.B.5 Disposal of Nonhazardous and Nonregulated Waste 194 8.B.6 Treatment and Disposal Options 195 8.B.6.1 Treatment and Recycling 195 8.B.6.2 Disposal in the Sanitary Sewer 196 8.B.6.3 Release to the Atmosphere 196 8.B.6.4 Incineration 196 8.B.7 Monitoring Waste Services, Transport, and Off-Site Treatment and Disposal 197 8.B.7.1 Preparation for Off-Site Treatment or Disposal of Waste 198 8.B.7.2 Choice of Transporter and Disposal Facility 198 8.B.8 Liability Concerns 198 8.B.9 Manifesting Hazardous Wastes 199 8.B.10 Records and Record Keeping 199 8.C MULTIHAZARDOUS WASTE 201 8.C.1 Chemical–Radioactive (Mixed) Waste 202 8.C.1.1 Minimization of Mixed Waste 203 8.C.1.2 Safe Storage of Mixed Waste 203 8.C.1.3 Hazard Reduction of Mixed Waste 204 8.C.1.4 Commercial Disposal Services for Mixed Waste 204 8.C.2 Chemical–Biological Waste 205 8.C.2.1 Disposal of Chemically Contaminated Animal Tissue 206 8.C.2.2 Sewer Disposal of Chemical–Biological Liquids 206 183

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184 PRUDENT PRACTICES IN THE LABORATORY 8.C.2.3 Disinfection and Autoclaving of Contaminated Labware 206 8.C.2.4 Disposal of Chemically Contaminated Medical Waste and Sharps 206 8.C.2.5 Minimization Methods for Chemical–Biological Waste 207 8.C.3 Radioactive–Biological Waste 207 8.C.3.1 Off-Site Management of Low-Level Radioactive Waste 207 8.C.3.2 Disposal of Radioactive Animal Carcasses and Tissue 207 8.C.3.3 Disposal of Radioactive–Biological Contaminated Labware 208 8.C.3.4 Sewer Disposal of Radioactive–Biological Liquids 208 8.C.4 Chemical–Radioactive–Biological Waste 208 8.D PROCEDURES FOR THE LABORATORY-SCALE TREATMENT OF SURPLUS AND WASTE CHEMICALS 209 8.D.1 Treatment of Acids and Bases 209 8.D.2 Treatment of Other Chemicals 209

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185 MANAGEMENT OF WASTE 8.A INTRODUCTION 8.B.6.2, below). At this tier it is important for laboratory personnel and environmental health and safety (EHS) This chapter presents methods for the management staff to work cooperatively to determine the point and ultimate disposal of laboratory waste that may at which the chemical becomes regulated as a waste present chemical hazards, as well as those multihazard- and to ensure that requirements are met. In general ous wastes that contain some combination of chemical, terms, waste is defined as material that is discarded, radioactive, and biological hazards. The best strategy is intended to be discarded, or is no longer useful for for managing laboratory waste aims to maximize safety its intended purpose. This point may occur after the and minimize environmental impact, and considers chemical has left the laboratory, however, if the orga- these objectives from the time of purchase. As sug- nization has a way to reuse or redistribute the material gested in previous chapters, there is a strategic hierar- or to use it in another procedure. Note that regulators chy for managing chemicals and waste to accomplish may consider a material to be a waste if it is abandoned these objectives. or is inherently wastelike (e.g., spilled materials). The The initial responsibility for implementing this hi- determination of whether a waste is regulated as haz- erarchy rests with trained laboratory personnel. These ardous is usually made either by the institution’s EHS individuals are in the best position to know the chemi- staff or by employees of the waste disposal firm. cal and physical properties of the materials they have While the first two tiers are the preferred ways of used or synthesized. They are responsible for evaluat- managing chemical waste, the third strategic tier also ing hazards, providing information necessary to make provides safety and environmental benefits (see Sec- an accurate waste determination, and assisting in the tion 8.B.6). If waste cannot be prevented or minimized, evaluation of appropriate strategies for management, the organization should consider recycling chemicals minimization, and disposal. that can be recovered safely from the waste and the The overriding principle governing the prudent potential for recovering energy from the waste (e.g., handling of laboratory waste is that no activity should using solvent as a fuel). Although some laboratories begin unless a plan for the disposal of nonhazardous and distill waste solvents for reuse, these strategies are hazardous waste has been formulated. Application of this most commonly accomplished by sending the waste simple principle ensures that the numerous state and to a commercial recycling or reclamation facility or to federal regulatory requirements for waste handling a fuel blender. These strategies are described later in are met and avoids unexpected difficulties, such as the this chapter. generation of a form of waste (e.g., chemical, radioac- The fourth and final strategic tier for managing tive, biological) that the institution is not prepared to laboratory waste includes incineration, other treatment deal with. methods, and land disposal. Decisions within this tier There are four tiers to waste management to reduce consider the environmental fate of the waste and its its environmental impact: pollution prevention and constituents and process byproducts after it leaves source reduction; reuse or redistribution of unwanted, the institution or firm. As with other tiers, the goal is surplus materials; treatment, reclamation, and re- to minimize risk to health and the environment. Land cycling of materials within the waste; and disposal disposal is the least desirable disposal method. Al- through incineration, treatment, or land burial. The though modern hazardous waste landfills can contain first tier of this strategic hierarchy incorporates the waste for many decades, there is always a future risk of principles of green chemistry (see Chapter 5, sec- leaking, contaminated runoff or other harmful releases tion 5.B): pollution prevention and source reduction. to the environment. Laboratories that ship chemical Clearly, the best approach to laboratory waste is pre- waste off-site must address land disposal restrictions venting its generation. Examples include reducing the and treatability standards, which were put in place to scale of laboratory operations, reducing the formation discourage landfilling. Other reasons to consider envi- of waste during laboratory operations, and substituting ronmental fate include exhibiting good environmental nonhazardous or less hazardous chemicals in chemical stewardship, teaching students and employees respon- procedures. sible waste management practices, and maintaining a The second strategic tier is to reuse unwanted mate- good public image. rial, redistribute surplus chemicals, and reduce haz- Of course, all laboratories wish to avoid fines and ards. Practices that implement this strategy include sanctions from federal, state, and local regulators. purchasing only what is needed, keeping chemical Because these potential penalties can be significant, inventories to prevent the purchase of duplicates, this laboratory waste management guidance includes and reusing excess materials. Sanitary sewer disposal information on laws, regulations, rules, and ordinances of certain aqueous liquids is considered within this that are likely to be most important to people who work tier, although there are many restrictions (see section in laboratories and support laboratory operations.

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186 PRUDENT PRACTICES IN THE LABORATORY Please note, however, that this book is not a compli- the smallest quantity of hazardous material required ance manual, and as such, its compliance information and reusing materials are also effective means of mini- is incomplete. In particular, this chapter focuses on mizing generation of hazardous waste. federal rules that apply to laboratory waste but not the Before beginning a detailed discussion of the han- many different requirements particular to each state or dling of waste once it has been generated, it is impor- locale. Chapter 11 contains additional information on tant to understand the definition of waste, how it is the institutional regulation of laboratory waste (as well characterized, and the regulations that govern it. as other environmental requirements) to complement this chapter’s details of laboratory waste regulation. 8.B.2 Characterization of Waste There are many good compliance references to aug- ment this book, and regulatory agencies should not be Waste must be categorized as to its identity, constitu- overlooked as another source of helpful information. ents, and hazards so that it may be safely handled and Do not hesitate to seek legal advice when needed. managed. Categorization is necessary to determine a waste’s regulatory status, hazardous waste ID number, and treatability group, and to determine its proper U.S. 8.B CHEMICAL HAZARDOUS WASTE Department of Transportation (DOT) shipping name, and to meet other transport, treatment, and disposal 8.B.1 In-Laboratory Hazard Reduction requirements. The first and second tiers of waste management The great variety of laboratory waste makes waste broadly describe methods of reducing quantity and categorization challenging. Transport and waste regu- level of hazard of laboratory waste. Hazard reduction lations are written for commercially available high- is part of the broad theme of pollution prevention that volume chemicals, which may make it difficult to is encouraged throughout this book. From a chemist’s categorize some laboratory chemicals, such as experi- point of view, it is feasible to reduce the volume or mental or newly synthesized materials. Categorization the hazardous characteristics of many chemicals by procedures must account for the common laboratory conducting reactions and other hazard reduction pro- waste management practices of placing small contain- cedures in the laboratory. It is becoming increasingly ers of waste chemicals into a larger overpack drum, and common to include such reactions as the final steps in combining of many solvents and solutes into a single an experimental sequence. Such procedures, as part of drum of flammable liquids. an academic or industrial experiment, usually involve There are several acceptable information sources for small amounts of materials which can be handled eas- waste characterization, including the identity of the ily and safely by laboratory personnel. Performing a source or raw materials, in-laboratory test procedures hazard reduction procedure as part of an experiment (such as those described below), and analysis by an has considerable economic advantages by eliminating environmental laboratory. Generator knowledge can be the necessity to accumulate, handle, store, transport, used for waste characterization, such as the knowledge and treat hazardous waste after the experiment. Fur- of waste characteristics and constituents by laboratory thermore, the laboratory professional who generates personnel who conducted the process, procedure, or the potential waste often has the expertise and knowl- experiment. edge to safely handle the materials and perform hazard reduction procedures. 8.B.2.1 Characterization for Off-Site Management Conducting laboratory hazard reduction procedures for chemical hazardous waste makes most sense for When waste is to be shipped off-site for recycling, hard-to-dispose-of waste, such as multihazardous reclamation, treatment, or disposal, the waste charac- waste, or for small or remote laboratories that gener- terization information needed depends on the waste ate very small quantities of easily treatable hazardous management facility’s requirements and its permit. waste. In some cases, a simple procedure can make Analytical methods have been established by the U.S. waste suitable for sewer disposal. When it can be done Environmental Protection Agency (EPA), and environ- safely, knowledgeable laboratory staff may treat very mental laboratories that use EPA methods are often small amounts of reactives that would otherwise pose a certified or accredited. Most of these methods are for storage or transport risk. In some cases, waste is stabi- commercially available chemicals, and so approved lized or encapsulated to enable safe storage and trans- analytical procedures may not be available for some port. More details can be found in section 8.B.6, below. laboratory chemicals. It is important to work with Keeping up-to-date chemical inventories can also your waste disposal firm to determine how laboratory reduce the in-laboratory hazards by simply reducing waste is to be categorized. To avoid redundant analysis the quantity of hazardous material on-site. Ordering for recurring waste streams (e.g., chlorinated solvents,

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187 MANAGEMENT OF WASTE labpacks of organic solids), waste disposal firms and by your hazardous waste disposal firm. Understand off-site facilities often establish a waste-stream profile. that the following test procedures are only to provide In some cases, detailed analytical information is not additional information, and do not meet EPA regula- necessary if waste containers fall within the profile’s tory requirements for waste analysis. hazard classification. In general, precisely determining the molecular structure of the unknown material is not necessary. Hazard classification usually satisfies the regulatory re- 8.B.2.2 Identification Responsibilities of All quirements and those of the treatment disposal facility. Laboratory Personnel However, it is important to establish which analytical Because proper management and disposal of labora- data are required by the disposal facility. tory waste requires information about its properties, it Trained laboratory personnel who carry out the is very important that laboratory personnel accurately analytical procedures should be familiar with the char- and completely identify and clearly label all chemical acteristics of the waste and any necessary precautions. and waste containers in their laboratory, as well as Because the hazards of the materials being tested are maintain the integrity of source material labels. It is unknown, the use of proper personal protection and recommended that supplementary information be kept safety devices such as chemical hoods and shields is in a separate, readily available record (e.g., laboratory imperative. Older samples are particularly danger- information system, lab notebook), especially for very ous because they may have changed in composition, small containers or collections. In academic laborato- for example, through the formation of peroxides. (See ries where student turnover is frequent, identification Chapter 4, section 4.D.3.2, for information on the for- is particularly important for the materials used or gen- mation and identification of peroxides. See Chapter 6, erated. This practice is as important for small quantities section 6.G.3, for information on testing and disposal as it is for large quantities. of peroxides.) The following information is commonly required by treatment and disposal facilities before they agree to 8.B.2.3 Characterization of Unknowns handle unknown materials: Establishing the hazardous characteristics and evalu- ating the potential listing of clearly identified waste • physical description, is usually quite simple. Unidentified materials (un- • water reactivity, knowns) present a problem, however, because recy- • water solubility, cling, treatment, and disposal facilities need to know • pH, characteristics and hazards to manage waste safely. All • ignitability (flammability), chemicals must be characterized sufficiently for safe • presence of oxidizer, transportation off-site. • presence of sulfides or cyanides, Analysis of laboratory unknowns is expensive, espe- • presence of halogens, cially if EPA methods must be used, or the presence of a • presence of radioactive materials, constituent must be ruled out, and handling unknowns • presence of biohazardous materials, is risky due to the possible presence of unstable, reac- • presence of toxic constituents, tive, or highly toxic chemicals or byproducts. Although • presence of polychlorinated biphenyls (PCBs), expensive, some waste disposal firms offer on-site and services to categorize unknown laboratory waste to • presence of high-odor compounds. prepare it for shipment to their treatment facility. The following test procedures are readily accom- plished by trained laboratory personnel. The overall 8.B.2.4 In-Laboratory Test Procedures for sequence for testing is depicted in Figure 8.1 for liquid Unknowns and solid materials. When the identity of the material is not known, simple in-laboratory test procedures can be carried out • Physical description. Include the state of the to determine the hazard class into which the material material (solid, liquid), the color, and the con- should be categorized. Because the generator may be sistency (for solids) or viscosity (for liquids). For able to supply some general information, it may be liquid materials, describe the clarity of the solu- beneficial to carry out the test procedures before the tion (transparent, translucent, or opaque). If an materials are removed from the laboratory. Perform unknown material is a bi- or tri-layered liquid, these tests only if they can be done safely, and only if describe each layer separately, giving an approxi- they facilitate the characterization of the waste required mate percentage of the total for each layer. After

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188 PRUDENT PRACTICES IN THE LABORATORY FIGURE 8.1 Flowchart for categorizing unknown chemicals for waste disposal. This decision tree shows the sequence of tests to be performed to determine the appropriate hazard category of an unknown chemical. DWW, dangerous when wet; nos, not otherwise specified. Following categorization, select a hazard reduction procedure (section 8.D) or disposal option (section 8.B.6). taking appropriate safety precautions for han- rial supports its own combustion, it is a flammable dling the unknown, including the use of personal liquid with a flash point of less than 60 °C (140 ºF). protection devices, remove a small sample for use If the sample does not ignite, apply the ignition in the following tests. source again for 1 second. If the material burns, • Water reactivity. Carefully add a small quantity of it is combustible. Combustible materials have a the unknown to a few milliliters of water. Observe flash point between 60 and 93 °C (140 and 200 ºF). any changes, including heat evolution, gas evolu- • Presence of oxidizer. Wet commercially available tion, and flame generation. starch-iodide paper with 1 N hydrochloric acid, • Water solubility. Observe the solubility of the and place a small portion of the unknown on the unknown in water. If it is an insoluble liquid, wetted paper. A change in color of the paper to note whether it is less or more dense than water dark purple is a positive test for an oxidizer. The (i.e., does it float or sink?). Most nonhalogenated test can also be carried out by adding 0.1 to 0.2 g organic liquids are less dense than water. of sodium or potassium iodide to 1 mL of an acidic • pH. Test the material with multirange pH paper. If 10% solution of the unknown. Development of a the sample is water-soluble, test the pH of a 10% yellow-brown color indicates an oxidizer. To test aqueous solution. Carrying out a neutralization for hydroperoxides in water-insoluble organic titration may also be desirable or even required. solvents, dip the starch-iodine test paper into the • Ignitability (flammability). Place a small sample solvent, and let it dry. Add a drop of water to the of the material (<5 mL) in an aluminum test tray. same section of the paper. Development of a dark Apply an ignition source, typically a propane color indicates the presence of hydroperoxides. torch, to the test sample for 0.5 second. If the mate- • Presence of peroxides. The following tests detect

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189 MANAGEMENT OF WASTE 8.B.3 Regulated Chemical Hazardous most (but not all) peroxy compounds, including Waste all hydroperoxides. Please take care. (See Chapter 4, section 4.D.3.2, and Chapter 6, section 6.G.3, for An important question for planning within the information on the hazards of peroxides.) laboratory is whether a waste is regulated as a hazard- Peroxide test strips, which turn to an indicative ous waste, because regulated hazardous waste must color in the presence of peroxides, are available be handled and disposed of in specific ways. This de- commercially. Note that these strips must be air termination has important implications that can lead dried until the solvent evaporates and exposed to significant differences in disposal cost. Regulatory to moisture for proper operation. definitions often differ from common definitions. EPA Add 1 to 3 mL of the liquid to be tested to an defines chemical hazardous waste under the Resource equal volume of acetic acid, add a few drops Conservation and Recovery Act of 1978 (RCRA 40 CFR of 5% aqueous potassium iodide solution, and Parts 260-272). EPA and RCRA establish the federal shake. The appearance of a yellow to brown standards for chemical hazardous waste. The U.S. Nu- color indicates the presence of peroxides. Alter- clear Regulatory Commission (USNRC) defines radio- natively, addition of 1 mL of a freshly prepared active waste. Hazardous biological waste is regulated 10% solution of potassium iodide to 10 mL of less stringently under federal law, but its management an organic liquid in a 25-mL glass cylinder pro- is addressed in the Occupational Safety and Health duces a yellow color if peroxides are present. Administration (OSHA) bloodborne pathogens stan- Add 0.5 mL of the liquid to be tested to a mix- dards and in Biosafety in Microbiological and Biomedical ture of 1 mL of 10% aqueous potassium iodide Laboratories (BMBL; HHS/CDC/NIH, 2007a). solution and 0.5 mL of dilute hydrochloric acid Note that, although close attention must be paid to to which has been added a few drops of starch the regulatory definitions and procedures that govern solution just prior to the test. The appearance the handling and disposal of waste, primary impor- of a blue or blue-black color within 1 minute tance must be given to the safe and prudent handling of indicates the presence of peroxides. all laboratory wastes. Evaluate unregulated wastes and None of these tests should be applied to materials consider special handling if they pose occupational, (such as metallic potassium) that may be contami- environmental, or unknown risks. nated with inorganic peroxides. (See Chapter 6, Chemical waste that is regulated as “hazardous section 6.G.3, for more information about perox- waste” is defined by EPA in either of two ways: (1) ide testing.) waste that has certain hazardous characteristics and • Presence of sulfide. Commercial test strips for the (2) waste that is on certain lists of chemicals. The first presence of sulfide are available, and their use is category is based on properties of materials that should recommended. If the test strips are not available be familiar to all trained laboratory personnel. The in the laboratory, the following test can be per- second category comprises lists, established by EPA, formed. Warning: This test produces hazardous of certain common hazardous chemicals and chemical and odiferous vapors. Use only small quantities wastes. These lists generally include materials that are of solution for the test and use appropriate ven- widely used and recognized as hazardous. Chemicals tilation. The test for inorganic sulfides is carried are placed on these RCRA lists primarily on the basis out only when the pH of an aqueous solution of of their toxicity. See below to determine if waste is the unknown is greater than 10. Add a few drops hazardous or not. of concentrated hydrochloric acid to a sample of Regardless of the regulatory definitions of hazard, the unknown while holding a piece of commercial understanding chemical characteristics that pose po- lead acetate paper, wet with distilled water, over tential hazards is a fundamental part of the education the sample. Development of a brown-black color and training of laboratory personnel. These character- on the paper indicates generation of hydrogen istics may be derived from knowledge of the properties sulfide. or precursors of the waste. The characteristics may also • Presence of cyanide. Commercial test strips for be established by specific tests cited in the regulations. the presence of cyanide are available, and their (Regulatory issues, specifically RCRA, are discussed use is strongly recommended. further in Chapter 11, section 11.E.1.) • Presence of halogen. Heat a piece of copper wire until red in a flame. Cool the wire in distilled or deionized water, and dip it into the unknown. 8.B.3.1 Definition of Characteristic Waste Again heat the wire in the flame. The presence of According to federal law, the properties of chemi- halogen is indicated by a green color around the cal waste that pose hazards are as follows. Note that wire in the flame.

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190 PRUDENT PRACTICES IN THE LABORATORY these definitions are unique, especially the definition 8.B.3.2 Definition of Listed Waste of waste having the characteristic of toxicity. A chemical waste that does not exhibit one of the above characteristics may still be regulated if it is a 1. Ignitability. Ignitable materials are defined as listed waste. Although EPA has developed several lists having one or more of the following charac- of hazardous waste, three regulatory lists are of most teristics: interest to trained laboratory personnel: (a) liquids that have a flash point of less than 60 °C (140 °F) or some other characteristic • F list: waste from nonspecific sources (e.g., spent that has the potential to cause fire; solvents and process or reaction waste); (b) materials other than liquids that are capable, • U list: hazardous waste (e.g., toxic laboratory under standard temperature and pressure, chemicals); and of causing fire by friction, adsorption of • P list: acutely hazardous waste [e.g., highly toxic moisture, or spontaneous chemical changes laboratory chemicals, that is, chemicals having a and, when ignited, burn so vigorously and lethal dose (LD50) of <50 mg/kg (oral, rat)]. persistently that they create a hazard; (c) f lammable compressed gases, including Of the listed wastes, the most common for laborato- those that form flammable mixtures; ries are the F wastes, which include many laboratory (d) oxidizers that stimulate combustion of or- solvents. These include halogenated solvents (methyl- ganic materials. ene chloride, tetrachloroethylene, and chlorinated fluo- Ignitable materials include most common or- rocarbons) and nonhalogenated solvents (xylene, ac- ganic solvents, gases such as hydrogen and hy- etone, ethyl acetate, ethyl benzene, ethyl ether, methyl drocarbons, and certain nitrate salts. isobutyl ketone, methanol, and n-butyl alcohol). Note 2. Corrosivity. Corrosive liquids have a pH ≤ 2 or that these are regulated under this listing only if they pH ≥ 12.5 or corrode certain grades of steel. Most have been used (spent). common laboratory acids and bases are corro- The other categories of listed waste common to sive. Solid corrosives, such as sodium hydroxide laboratories are the U and P lists, which include many pellets and powders, are not legally considered chemicals frequently found in laboratories. U and P by RCRA to be corrosive. However, trained lists pertain to laboratory personnel must recognize that such materials are extremely dangerous to skin and • waste chemicals that have not been used, because eyes and must be handled accordingly. once used, the U or P listing does not apply; 3. Reactivity. The reactivity classification includes • spills and spill cleanup material from U- or P- substances that are unstable, react violently with listed compounds; and water, detonate if exposed to some initiating • rinsate from triple rinsing of empty containers of P source, or produce toxic gases. Alkali metals, per- compounds (described below), which is collected oxides and compounds that have peroxidized, and handled as hazardous. and cyanide or sulfide compounds are classed as reactive. 4. Toxicity. Toxicity is established through the tox- 8.B.3.3 Determining the Regulatory Status of a icity characteristic leaching procedure (TCLP) Waste test, which measures the tendency of certain The EPA regulations place the burden of determining toxic materials to be leached (extracted) from whether a waste is regulated as hazardous and in what the waste material under circumstances assumed hazard classification it falls on the waste generator. to reproduce conditions of a landfill. The TCLP Most laboratories rely on their EHS staff or their waste list includes a relatively small number of indus- disposal firm to determine EPA and DOT regulatory trially important toxic chemicals and is based categories (such as EPA ID numbers and transportation on the leachate concentration, above which a classes), as well as waste characterization information waste is considered hazardous. Failure to pass needed by the recycling, treatment, or disposal facility. the TCLP results in classification of a material Testing is not necessarily required, and in most cases as a toxic waste. The TCLP test is primarily for trained laboratory personnel are able to provide suf- solid materials; liquids are typically evaluated ficient information about the waste to categorize it by on a straight concentration basis. TCLP analyses general hazard categories. If the waste is not a common are usually performed by environmental testing chemical with known characteristics, enough informa- laboratories. tion about it must be supplied to satisfy the regulatory

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191 MANAGEMENT OF WASTE requirements and to ensure that it can be handled and unless a plan for disposal of all waste, hazardous and disposed of safely. The information needed to charac- nonhazardous, has been formulated. terize a waste also depends on the method of ultimate The accumulation and temporary storage of waste disposal. (See the discussion of disposal methods in in the laboratory is called satellite accumulation. The sections 8.B.6 to 8.B.7, below.) legal standards for satellite accumulation are included in this section; they are also good practices for the management of nonregulated waste. To ensure security 8.B.3.4 Empty Containers and management oversight, chemical waste should be The rules for disposal of empty hazardous waste accumulated at or near the point of generation, and containers, and cleaning the empty containers, are under control of laboratory personnel. Note that there complex. A container or inner liner of a container that is an optional alternative federal standard for the ac- contained hazardous waste is “empty” under federal cumulation of waste within laboratories of colleges, regulations if all waste has been removed by standard universities, teaching hospitals, and certain nonprofit practice and no more than 2.5 cm (1 in.) of residue, or research facilities associated with colleges or universi- 3% by weight of containers less than 110 gal, remains. ties. This is described in section 8.B.4.3, below. If the container held acute hazardous waste, triple Each category of waste has certain precautions rinsing or equivalent measures are required before the and appropriate disposal methods. Below is a list of container is “empty” within the federal regulations. requirements and good practices for accumulating The rinsate must be collected and handled as acutely chemical waste in the laboratory: hazardous waste. “Empty” containers are no longer subject to federal regulation. • Collect hazardous or flammable waste solvents These are minimum standards. If empty containers in an appropriate container pending transfer to are to be recycled or disposed of in the normal trash, the institution’s central facility or satellite site for it is recommended that labels be removed from empty chemical waste handling or pickup by commercial hazardous waste containers, and that they be emptied disposal firm. Often, different kinds of waste are as much as possible. Consider rinsing emptied contain- accumulated within a common container. ers with water or a detergent solution. Resulting rinsate • Take care not to mix incompatible waste. This is a from containers previously holding acutely hazardous special concern with commingled waste solvents, waste are hazardous waste and must be disposed of which must be chemically compatible to ensure accordingly. Rinsate resulting from cleaning of other that heat generation, gas evolution, or another hazardous waste containers is hazardous waste if it reaction does not occur. (See the discussion of exhibits EPA’s hazardous waste characteristics of ignit- commingling in section 8.B.4.2, below.) For ex- ability, corrosivity, reactivity, or toxicity. It is prudent ample, waste solvents can usually be mixed for to follow these guidelines for disposing of empty con- disposal, with due regard for the compatibility of tainers of nonhazardous and nonregulated laboratory the components. chemicals. • Keep wastes segregated by how they will be Properly cleaning containers as described above, and managed. For example, because nonhalogenated recycling or disposing of them with the normal trash, solvents are more suitable for fuel blending, many reduces costs as well as the volume of hazardous waste laboratories collect halogenated and nonhaloge- generated. Alternatively, some firms and institutions nated solvent wastes separately. decide that it is more convenient to handle all empty • Collect waste in dependable containers that are chemical containers from laboratories as hazardous compatible with their contents. Keep containers waste and dispose of them accordingly. This especially closed except when adding or subtracting waste. makes sense if the rinsate is hazardous. Separate containers of incompatible materials physically or otherwise stored in a protective manner. (See Chapter 5, section 5.E.2, for storing 8.B.4 Collection and Storage of Waste chemicals according to their compatibility.) • Use an appropriate container for the collection 8.B.4.1 Accumulation of Waste at the Location of of liquid waste. Glass bottles are impervious to Generation most chemicals but present a breakage hazard, Laboratory experiments generate a great variety and narrow-neck bottles are difficult to empty. of waste, including used disposable laboratory ware, The use of plastic (e.g., polyethylene jerry cans) filter media and similar materials, aqueous solutions, or metal (galvanized or stainless steel) safety con- and hazardous and nonhazardous chemicals. As stated tainers for the collection of liquid waste is strongly in the introduction to this chapter, begin no activity encouraged. Note that flame arresters in safety

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192 PRUDENT PRACTICES IN THE LABORATORY containers can easily become plugged if there is with the waste and its generation, need to be actively sediment and may need to be cleaned occasion- involved in waste identification and management ally. Do not store amines or corrosive materials in decisions, so that the waste is managed safely and ef- metal containers. ficiently. Often the appropriate time to decide to recycle • Do not use galvanized steel safety cans for haloge- or reuse surplus materials is shortly after the waste is nated waste solvents because they tend to corrode generated, rather than when they are sent for disposal. and leak. Once combined with other waste materials, recycling • As detailed below, clearly and securely label or reuse may be more difficult. Evaluate all the costs waste containers with their contents. and benefits of either decision at this time. • Securely cap waste containers when not in imme- Safety considerations must be of primary concern. diate use. To minimize releases to the atmosphere, Store waste in clearly labeled containers in a desig- when a funnel is used either immediately reclose nated location that does not interfere with normal the container or use a capped waste funnel. Do laboratory operations. Ventilated storage may be ap- not use the same funnel for containers containing propriate. Use secondary containment such as trays, incompatible waste types. for spills or leakage from the primary containers. Many • Collect aqueous waste separately from organic states require the use of secondary containment for solvent waste. Some laboratories may be served wastes in satellite accumulation areas. by a wastewater treatment facility that allows the Federal regulations allow the indefinite accumula- disposal of aqueous waste to the sanitary sewer if tion of up to 55 gal of hazardous waste or 1 qt of acutely it falls within a narrow range of acceptable waste hazardous waste at or near the point of generation. types. Thus, solutions of nonhazardous salts or However, prudence dictates that the quantities ac- water-miscible organic materials may be accept- cumulated are consistent with good safety practices. able in some localities. Solutions containing flam- Furthermore, satellite accumulation time must be con- mable or hazardous waste, even if water-miscible, sistent with the stability of the material. The general are almost never allowed, and water-immiscible recommendation is that waste not be held for more substances must never be put down the drain. than 1 year; some states specifically set this limit for Collect aqueous waste for nonsewer disposal in a satellite accumulation time. Within 3 days of the time container selected for resistance to corrosion. Do that the amount of waste exceeds the 55-gal (or 1-qt) not use glass for aqueous waste if there is danger limit, manage it under the storage and accumulation of freezing. Depending on the requirements of the time limits required at a central accumulation area, as disposal facility, adjustment of the pH of aqueous described below. waste may be required. Such adjustment requires Packaging and labeling are key parts of this initial in- consideration of the possible consequences of the laboratory operation. Label every container of hazard- neutralization reaction that might take place: gas ous waste with the material’s identity and its hazard evolution, heat generation, or precipitation. (e.g., flammable, corrosive) and the words “hazardous • Place solid chemical waste, such as reaction by- waste.” Although the identity need not be a complete products or contaminated filter or chromatogra- listing of all chemical constituents, knowledgeable phy media, in an appropriately labeled container laboratory professionals or waste handlers should be to await disposal or pickup. Segregate unwanted able to evaluate the hazard. However, when compat- reagents for disposal in their original containers, ible wastes are collected in a common container, keep a if possible. If original containers are used, labels list of the components to aid in later disposal decisions. should be intact and fully legible. Make every Labeling must be clear and permanent. Although fed- effort to use, share, or recycle unwanted reagents eral regulations do not require posting the date when rather than commit them to disposal. (See Chapter satellite accumulation begins, some states do require 5, sections 5.D and 5.E, for a discussion of labeling this. The institution may suggest that this information alternatives.) be recorded as part of its chemical management plan. • Consider how to dispose of nonhazardous solid waste in laboratory trash or segregate it for re- 8.B.4.2 Accumulation of Waste in a Central Area cycling. Check the laboratory chemical safety summary, material safety data sheet, or other ap- The central accumulation area is an important com- propriate reference to determine toxicity. Consult ponent in the organization’s chemical management institutional policy on nonhazardous solid waste plan. In addition to being the primary location where disposal. waste management occurs, it may also be the location where excess chemicals are held for possible redistribu- Trained laboratory personnel, who are most familiar tion. Along with the laboratory, the central accumula-

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193 MANAGEMENT OF WASTE tion area is often where hazard reduction of waste takes trained in correct handling of the materials as well as place through allowable on-site treatment processes. contingency planning and emergency response. The The central accumulation area is often the appropri- area should be secure, and employees should be en- ate place to accomplish considerable cost savings by couraged to report any suspicious activity. Employees commingling (i.e., combining) similar waste materials. should know how to activate alarms, how to use fire ex- This is the process where compatible wastes from vari- tinguishers and other emergency response equipment, ous sources are combined prior to disposal. Commin- how to exit, and the location of the exterior assembly gling is particularly suitable for waste solvents because point. Be sure to document training and provide peri- disposal of liquid in a 55-gal drum is generally much odic refreshers. less expensive than disposal of the same volume of liq- Transportation of waste from laboratories (satellite uid in small containers. Because mixing waste requires accumulation areas) to the central accumulation area transfer of waste between containers, the identity of also requires specific attention to safety. Transport ma- all materials must be known and their compatibility terials in appropriate and clearly labeled containers. understood. Although these procedures are very cost- Make provision for spill control in case of an accident effective, they require additional safety precautions, during transportation and handling. Larger institu- including the use of personal protective equipment tions are advised to have an internal tracking system and special and engineering controls. In addition to to follow the movement of waste. If public roads are the facility needs described below, commingling areas used to transport laboratory waste, additional DOT require non-explosive electrical systems, grounding packaging, marking, labeling, and manifesting regula- and bonding between floors and containers, nonspark- tions may apply, as described below. ing conductive floors and containers, and specialized Final preparations for off-site disposal usually occur ventilation systems. A walk-in fume hood is often at the central accumulation area. Decisions on disposal used for both solvent commingling and the storage of options are best made here as larger quantities of waste commingling equipment. It is important to design the are gathered. Identification of unknown materials not process to minimize lifting, awkward procedures that carried out within the laboratory must be completed may cause injury, and the handling of heavy drums at this point because unidentified waste cannot be and equipment. shipped to a disposal site. In some cases the disposal method and ultimate fate Your hazardous waste disposal firm is frequently of the waste require that different wastes not be accu- involved with this phase of waste management. The mulated together. For example, if commingled waste decision of whether to involve a hazardous waste dis- contains significant amounts of halogenated solvents posal firm, how, and when is largely based on logistics (usually >1%), disposing of the mixture can be con- and economics. Table 8.1 describes the tasks involved siderably more expensive. In such cases segregation of in initiating off-site disposal and provides recom- halogenated and nonhalogenated solvents is economi- mendations for what should be done in-house by staff cally favorable. and what should be contracted to professional service According to federal regulations, storage at a central companies. accumulation area is normally limited to 90 days, al- Laboratory waste typically leaves the generator’s though more time is allowed for small-quantity genera- facility commingled in drums as compatible wastes tors or other special situations (180 or 270 days). The or within a labpack. Labpacks are containers, often count begins when the waste is brought to the central 55-gal drums, in which small containers of waste are accumulation area from the laboratory or satellite ac- packed with an absorbent material. Labpacks had been cumulation area. A special permit is required for storage used as the principal method for disposing of labora- tory waste within a landfill. However, recent landfill beyond the above limits. Obtaining such a permit is usually disposal restrictions severely limit landfill disposal of too expensive and too time-consuming for most laboratory operations. (See RCRA and Chapter 11, section 11.E.1, hazardous materials. Thus, the labpack has become for more information.) principally a shipping container. The labpack is taken Store waste materials within a central accumulation to a permitted treatment, storage, and disposal facility area in appropriate and clearly labeled containers and (TSDF), where it is either incinerated or unpacked and separate them according to chemical compatibility the contents redistributed for safe, efficient, and legal as noted in Chapter 5, section 5.E.2. The label must treatment and disposal. include the accumulation start date and the words If chemical hazardous waste is being accumulated “hazardous waste.” for recycling (e.g., waste lead, solvents for redistilla- Central accumulation areas should have fire sup- tion), federal law requires 75% or more of these materi- pression systems, ventilation, and dikes to avoid sewer als to be recycled or disposed of in each calendar year. contamination in case of a spill. Employees must be

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200 PRUDENT PRACTICES IN THE LABORATORY Example of Uniform Hazardous Waste Manifest. FIGURE 8.2 Figure 8.2.eps bitmap

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201 MANAGEMENT OF WASTE tion. Records of costs, internal tracking, and so forth tance for accomplishing the objectives of the Pollution can provide information on the success of the hazard- Prevention Act. ous waste management program. • Source reduction. Pollution should be prevented or reduced at the source whenever feasible. 8.C MULTIHAZARDOUS WASTE • Recycling. Pollution that cannot be prevented Multihazardous waste is a waste that presents any should be recycled in an environmentally safe combination of chemical, radioactive, or biological haz- manner whenever feasible. ards. This array of waste constituent hazards makes the • Treatment. Pollution that cannot be prevented or management of multihazardous wastes difficult and recycled should be treated in an environmentally complex. For example, low-level mixed waste (LLMW) safe manner whenever feasible. is a multihazardous waste that contains both RCRA • Disposal. Disposal or other release into the envi- hazardous wastes that EPA regulates and low-level ronment should be employed only as a last resort radioactive wastes (LLW or LLRW) that the USNRC and should be conducted in an environmentally regulates. The hazardous characteristics, treatment safe manner. methods, and disposal requirements for these wastes are different and often incompatible. Other factors that Federal agencies are required to promote programs further complicate the management of multihazard- to advance this policy within their agencies and nation- ous wastes include a complex federal, state, and local wide. The major research agencies within the federal regulatory framework; limited disposal options; and government, and particularly the Department of En- high disposal costs. Commercial treatment or disposal ergy, National Institutes of Health (NIH), and EPA, are facilities for multihazardous waste from laboratories providing leadership in implementing the nation’s pol- are scarce. There is little incentive for the development lution prevention policy, and are achieving results in of a commercial market to treat and dispose of labora- source reduction. For example, NIH’s low-level mixed tory multihazardous waste because most of the waste waste (LLMW) minimization program demonstrated that laboratories generate is unique to laboratories and that a significant amount of mixed waste currently be- small in volume. The management of multihazardous ing generated can be reduced or eliminated. References waste is particularly challenging for research labora- found on the accompanying CD provide more detail tories where there are frequent changes in protocols, about the source reduction and pollution prevention procedures, materials, and waste generating processes. initiatives of those agencies, the achievements of which These difficult and complex management issues can have encouraged academic research universities and also make it difficult to promote and sustain prudent corporate research facilities to focus their pollution pollution prevention practices. prevention programs on source reduction. EHS pro- Medical, clinical, forensic, and environmental labo- grams at these institutions often share information on ratories, and biomedical, biochemical, radiological, their Web sites regarding source reduction, recycling, and other types of research laboratories generate treatment, and disposal. multihazardous waste. Prudent management of these Prudent waste management methods include a wastes is necessary to protect the health and safety of commitment by senior management to develop and all laboratory personnel who handle, process, and store support a waste minimization program. The program the waste for disposal, and to minimize the potential of development should involve experienced laboratory harm to public health and the environment. A further personnel in planning waste minimization strategies objective of prudent management of multihazardous and identifying source reduction options, such as waste is to promote excellence in environmental stew- incorporating pollution prevention goals into project ardship. The Congress established a federal initiative proposals. Training of laboratory personnel to recog- for preventing or reducing pollution in the Pollution nize opportunities for source reduction, reviewing Prevention Act of 1990. This initiative can serve as a research proposals to ensure adoption of available guide for developing prudent practices for managing source reduction strategies, improving compliance multihazardous wastes. with regulatory requirements, and institutional policy The Pollution Prevention Act of 1990 established a are among the new management initiatives at research national policy that emphasizes source reduction as institutions promoting pollution prevention. Multihaz- the most desirable approach for preventing or reduc- ardous waste requires complex attention because of ing pollution. The policy created a new hierarchy for its combination of hazards and regulatory controls, as the management of hazardous wastes. The elements of detailed in the following guidelines: that hierarchy are listed in order of priority and impor-

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202 PRUDENT PRACTICES IN THE LABORATORY Assess the risk posed by the hazardous character- atic for waste management. “Mixed waste” is the regu- istics of the waste. A primary purpose of the risk as- latory term for multihazardous waste that exhibits both sessment is to determine which hazardous constituent chemical and radioactive hazards (40 CFR § 266.210). of the multihazardous waste presents the greatest risk. Mixed wastes are defined by EPA as “wastes that con- This knowledge can help identify source reduction and tain a chemical hazardous waste component regulated treatment possibilities to reduce the risk of the waste. under Subtitle C of RCRA and a radioactive component An assessment that determines that a waste constitu- consisting of source, special nuclear, or byproduct ma- ent does not present a significant risk may provide an terial regulated under the Atomic Energy Act of 1946 opportunity for regulatory flexibility. For example, the (AEA)” (EPA, 1986). The complex challenge of manag- USNRC or state authority may allow a licensee to man- ing waste controlled by two federal agencies was re- age a chemical–radioactive waste as a chemical waste duced by the EPA Final Rule on the storage, treatment, without regard to radioactivity when the radioactive transportation, and disposal of low-level mixed waste constituent concentration is less than what the USNRC of 2001 (40 CFR Part 266, Subpart N). The rule condi- specifies for an unrestricted area. tionally exempts the hazardous waste constituents of Minimize the hazardous constituents in the waste. LLMW from RCRA during storage and treatment. This Consider applying the waste minimization methods change provides more opportunities for treatment of specific to each hazardous constituent of the waste. the chemical constituents in LLMW, enabling disposal This strategy could result in reducing or eliminating as a single hazard constituent LLRW. State regulations one hazardous constituent from the waste stream may continue to inhibit laboratory and on-site minimi- and managing the waste as a single-hazard waste. zation, storage, and treatment of mixed waste. The rule For example, the substitution of nonignitable liquid applies only to LLMW that meets the specified condi- scintillation fluid (LSF) for toluene-based LSF reduces tions and is generated under a single USNRC license or a chemical–radioactive waste to a radioactive waste. USNRC Agreement State license. The rule also exempts Determine options for managing the multihazard- LLMW and hazardous naturally occurring or acceler- ous waste. Waste management options include recy- ator-produced radioactive materials (NARM) waste cling, laboratory methods, management at institutional from RCRA manifest, transportation, and disposal waste facilities, and treatment and disposal at com- requirements that adhere to the specified conditions. mercial sites. Options can vary considerably between Under this conditional exemption, the waste remains laboratories depending upon institutional capabilities subject to manifest, transport, and disposal require- and state and local laws. It may be appropriate to man- ments under the USNRC (or USNRC Agreement State) age the waste in order of risk priority, from high to low regulations for LLW or eligible NARM. This flexibility risk. Options must be compatible with all hazards, and allows on-site storage of LLMW for periods longer than combinations of waste management methods may be 90 days. The management opportunity to treat the haz- limited by their order of application. Reject any combi- ardous waste constituents of LLMW on-site can reduce nation or sequence of methods that may create an un- the dependence on services provided by commercial reasonable risk to waste handlers or the environment, treatment and disposal facilities. or that might increase the overall risk. If an option has Examples of laboratory mixed waste include a clear advantage in efficiency and safety, it should have highest priority. For example, if safe facilities are • used flammable (e.g., toluene) liquid scintillation available on-site, hold short-half-life radioactive waste cocktails, for decay before managing it as a chemical or biological • phenol–chloroform mixtures from extraction of waste. The EPA Final Rule on the storage, treatment, nucleic acids from radiolabeled cell components, transportation, and disposal of low-level mixed waste • aqueous solutions containing radioactive material will allow holding the waste for longer than 90 days. and chloroform that occur in solutions generated Select a single management option when possible. by the neutralization of radioactive trichloroacetic Some waste management methods are appropriate for acid solutions, more than one waste hazard. Some multihazardous • certain gel electrophoresis waste (e.g., methanol waste can be disposed of safely in the sanitary sewer or acetic acid containing radionuclides), and when allowed by the local POTW. • lead contaminated with radioactive materials. Mixed waste produced at university, clinical, and 8.C.1 Chemical–Radioactive (Mixed) Waste medical research laboratories is typically a mixture of LLMW is the most common form of multihazardous a LLRW and chemical hazardous waste. Mixed waste waste generated in laboratories and the most problem- from nuclear and energy research laboratories can

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203 MANAGEMENT OF WASTE include both low- and high-level (e.g., spent nuclear Some simple operational improvements can help fuels) radioactive materials combined with chemical minimize mixed waste. Purchase chemicals and radio- hazardous waste. Common laboratory waste manage- active materials in quantities necessary for a planned ment methods for radioactive constituents in waste experiment to avoid creating surplus materials that include storage for decay and indefinite on-site storage, may end up as waste. Establish procedures that will burial at a LLRW site, incineration, and sanitary sewer prevent commingling radioactive waste with noncon- disposal. Disposal options for mixed waste are usually taminated materials and trash. very expensive, and for many types of mixed waste, Consider substituting a less-hazardous constituent there are no management options other than indefinite for either the chemical or the radioactive source of storage on-site. the mixed waste. The experimenter should use the minimum activity necessary and select the radionu- clide with the most appropriate decay characteristics. 8.C.1.1 Minimization of Mixed Waste Examples include the following: Rigorous application of waste minimization prin- ciples can often solve the problems of managing mixed • Use nonignitable scintillation fluid (e.g., phenyl- waste. Such efforts are most successful when scientists xylylethane, linear alkylbenzenes, and diisopro- and EHS staff work together to evaluate laboratory pylnaphthalene) instead of flammable scintillation processes. A successful collaborative minimization fluid (e.g., toluene, xylene, and pseudocumene). initiative undertaken by the NIH Mixed Waste Mini- LSF that is sold as being “biodegradable” or mization Program demonstrated that the ultraviolet “sewer disposable” is more appropriately labeled peroxidation treatment of aqueous mixed waste could as “nonignitable” because biodegradability in the reduce or eliminate a large portion of the mixed waste sanitary sewer can vary considerably with the lo- generated in the NIH research laboratories. This treat- cal treatment facility. ment method degrades hazardous organic compounds • Use nonradioactive substitutes such as scintil- lation proximity assays for phosphorus-32 (32P) in high-volume aqueous mixed waste streams. The or sulfur-35 (35S) sequencing studies or 3H cation removal efficiency for a number of volatile and semi- volatile compounds is in excess of 99.99%. The treated assays, and enhanced chemiluminescence as a substitute for 32P and 35S DNA probe labeling and waste can be discharged to the sanitary sewer (Rau, 1997). Southern blot analysis. Modifying laboratory processes, improving opera- • Substitute enriched stable isotopes for radionu- tions, or using substitute materials are approaches that clides in some cases. Mass spectrometry (MS) can achieve minimization of mixed waste. Examples of techniques, such as inductively coupled plasma- these approaches include the following: MS, are beginning to rival the sensitivity of some counting methods. Examples include use of oxy- gen-18 (18O) and deuterium (2H) with mass spec- • Use 2.5-mL scintillation vials (“minivials”) rather than 10-mL vials. Adapters are available for scin- trometry detection as substitutes for oxygen-19 (19O) and 3H. tillation counters with 10-mL vial racks. • Count phosphorus-32 (32P) without scintillation • S ubstitution of shorter-half-life radionuclides fluid by the Cerenkov method on the tritium (3H) such as 32P (t1/2 = 14 days) for phosphorus-33 (33P) (t1/2 = 25 days) in orthophosphate studies, or 33P setting of a liquid scintillation counter (approxi- mately 40% efficiency); iodine-125 (125I) can be or 32P for 35S (t1/2 = 87 days) in nucleotides and deoxynucleotides. In many uses, iodine-131 (131I) counted without scintillation fluid in a gamma (t1/2 = 8 days) can be substituted for 125I (t1/2 = 60 counter. • Use microscale chemistry techniques. days). Additional exposure precautions may be • Eliminate the methanol/acetic acid (chemical) required. and radioactive mixed hazards in gel electropho- resis work by skipping the gel-fixing step if it is 8.C.1.2 Safe Storage of Mixed Waste not required. • Line lead containers with disposable plastic or Store waste containing short-half-life radionuclides use alternative shielding materials to prevent lead for decay prior to subsequent waste management pro- contamination by radioactivity. cessing and disposal. On-site decay-in-storage of LLW • Reduce the volume of dry waste by compaction of is very efficient and minimizes handling and transpor- contaminated waste gloves, absorbent pads, and tation risks. Most institutions designate a room or facil- glassware. ity equipped with good ventilation, effluent trapping, and fire suppression to contain and manage on-site

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204 PRUDENT PRACTICES IN THE LABORATORY decay-in-storage. Laboratory decay-in-storage space • The worker can reduce the chemical hazard to a can provide safe storage for low-risk mixed wastes. safe level and then handle the material as only Laboratory storage is not appropriate for storage of a radioactive hazardous waste. Many low-level putrescent or reactive materials. radiation materials can then be allowed to decay The specific USNRC requirements for decay-in- to a safe level, following which simple disposal is storage of radioactive waste are usually detailed in the allowable. institution’s license. Decay-in-storage is usually limited • Some radioactive methanol–acetic acid solutions to half-lives of less than 65 days. When the short-half- from gel electrophoresis can be recycled via dis- life radionuclides have decayed to background levels tillation and the methanol reused. The solution (the length of time depending on the initial radioactiv- is neutralized prior to distillation to protect the ity level but typically defined as a storage period of distillation equipment from corrosion and to at least 10 half-lives), the chemical–radioactive waste reduce the level of methyl acetate formed during can be managed as a chemical waste. After the decay the process. period, USNRC licenses usually require that the mixed • The volume of waste phenol, chloroform, metha- waste be surveyed for external radiation prior to releas- nol, and water containing radionuclides can be ing it to the chemical waste stream. reduced by separating the nonaqueous portion Storage of mixed waste for decay for more than 90 using a separatory funnel. After separation, the or- days may require the approval of the state chemical ganic phase can be distilled to produce chloroform hazardous waste authority. In permitted storage facili- waste, which may contain levels of radioactivity ties, storage may be limited to 1 year for some types of below license limits for radioactive waste. The still mixed waste. Workers should contact their institution’s bottom and aqueous phase must be handled as a EHS staff or local hazardous waste agency to determine mixed waste. their regulatory status and requirements for storing • High-performance liquid chromatography, used mixed waste for decay. to purify radiolabeled proteins and lipids, can generate a waste radioactive solution of aceto- nitrile, water, methanol, acetic acid, and often a 8.C.1.3 Hazard Reduction of Mixed Waste small amount of dimethylformamide. When the Chemical hazards can be reduced by carrying out solution is distilled by rotary flash evaporation, various common chemical reactions with the waste in the distillate of acetonitrile, methanol, and water the laboratory. However, “treatment” of chemical haz- is nonradioactive and can be handled as a chemi- ardous waste has regulatory implications that must be cal hazardous waste. The radioactive still bottom, considered. Many of the same considerations apply to containing 1 to 5% methanol and acetic acid, can treatment of mixed waste. usually be neutralized, diluted, and disposed of Nevertheless, there are still justifiable and legal in the sanitary sewer. reasons to carry out such operations in the laboratory • Aqueous solutions containing uranyl or thorium when hazards can be minimized safely. Neutraliza- compounds can be evaporated to dryness and the tion, oxidation, reduction, and various other chemical residues disposed of as radioactive waste. Because conversions as well as physical methods of separation of their toxicity, solidification may be necessary and concentration can be applied prudently to many prior to burial at a LLRW site. • Activated carbon, Molecular Sieves®, synthetic laboratory-scale mixed wastes. However, the dual char- acter of the hazard, chemical and radioactive, requires resins, and ion-exchange resins have been used that additional precautions be exercised. Treatment for with varying success in the separation of chemi- the chemical hazard must not create a radioactivity risk cal and radioactive waste constituents. Activated for personnel or the environment. For example, vapors carbon has been used to remove low concentra- or aerosols from a reaction, distillation, or evaporation tions of chloroform (less than 150 ppm) from must not lead to escape of unsafe levels of radioactive aqueous mixed waste solutions. However, acti- materials into the atmosphere. Laboratory chemical vated carbon is not suitable for high concentra- hoods appropriate for such operations should be de- tions of phenol–chloroform or acetonitrile–water mixed waste. Amberlite® XAD resin, a series of signed to trap any radioactive effluent. When mixed Amberlite® polymeric absorbent resins used in waste is made chemically safe for disposal into the sanitary sewer, the laboratory must ensure that the chromatography, has been shown to be effective in radioactivity hazard is below the standards set by the removing the organic constituents from aqueous POTW. Several examples for reducing the hazard of phenol, chloroform, and methanol solutions, leav- mixed waste are described below: ing an aqueous solution that can be managed as

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205 MANAGEMENT OF WASTE a radioactive waste. Chemical constituents can be or for lead-contaminated oils. Commercial disposal separated from mixed waste by using supercriti- capacity likewise does not exist for high concentrations cal fluid extraction (e.g., carbon dioxide), which is of halogen-containing organics and other TCLP waste, now available commercially. such as waste that contains chloroform. • Surface contamination from radioactively con- taminated lead can be removed by dipping the 8.C.2 Chemical–Biological Waste contaminated lead into a solution of 1 M hydro- chloric acid. After rinsing the lead with water, it Medical, clinical, and biomedical research laborato- usually can be documented as nonradioactive. ries generate waste that contains potentially infectious The acidic wash and rinse solutions contain radio- materials and viable agents that are capable of causing nuclides and lead and must be handled as mixed human disease. Biohazardous wastes can include tis- waste. However, decontaminating the lead results sues and carcasses of experimental animals involved in a smaller mass of mixed waste and allows the in infectious disease studies; cell cultures of infectious decontaminated lead to be reused or recycled. agents; contaminated sharps, gloves, gowns, glass- Commercial rinse products are also available for ware, and instruments; and blood and other clinical this purpose. specimens. Biohazardous waste presents a hazard to • Incineration is advantageous as a treatment for persons who handle the waste within the generat- many types of chemical–radioactive waste, es- ing facility. Waste decontamination is the treatment pecially those that contain toxic or flammable method to control or eliminate the exposure hazard organic chemicals. Incineration can destroy oxi- prior to waste handling and disposal. The OSHA Oc- dizable organic chemicals in the waste. To comply cupational Exposure to Bloodborne Pathogens rule with radionuclide release limits, USNRC licensees (29 CFR § 1910.1030) established federal requirements need to control emissions and may need to restrict for the collection and containment of certain labora- the incinerator’s waste feed. Radioactive ash is tory wastes that contain human blood or body fluids typically managed as a radioactive waste. It is for the purpose of preventing exposure of personnel important to keep toxic metals (e.g., lead, mer- to bloodborne pathogens. This rule promotes the use cury) out of the incinerable waste so that the ash is of standard microbiological practices including safe not chemically hazardous according to the TCLP practices for handling biohazardous wastes. The rule test. On-site incineration minimizes handling also requires the treatment of all contaminated waste and transportation risks; however, incineration of from research laboratories handling human immuno- chemical waste is regulated by EPA and requires deficiency virus (HIV) and hepatitis B virus (HBV) and a permit, which is beyond the resources of most other bloodborne pathogens by incineration or decon- laboratory waste generators. tamination by a method known to destroy the patho- gens within the waste materials. Federal regulations regarding transport and incineration may apply to the 8.C.1.4 Commercial Disposal Services for Mixed off-site management of nonlaboratory biohazardous Waste waste, such as waste generated in medical or health Because of the great variety of laboratory mixed care settings. Several states and local jurisdictions regu- waste, it is often difficult to find a facility that can late the treatment and disposal of biohazardous wastes. manage both the radioactive and the chemical hazards The Centers for Disease Control and Prevention of the waste. In general, existing commercial disposal (CDC) of the U.S. Department of Health and Human facilities are in business to manage mixed waste from Services and the Animal and Plant Health Inspection the nuclear power industry, not waste from laborato- Service of the U.S. Department of Agriculture pro- ries. Several commercial disposal facilities that accept mulgated rules under the Public Health Security and mixed waste from off-site generators do exist in the Bioterrorism Preparedness and Response Act of 2002 United States. These sites have the capacity to manage for the possession, use, and transfer of select agents LSF, halogenated organics, and other organic waste. and toxins. The rules require the destruction of select Treatment capacity exists for stabilization, neutraliza- agents that are contaminants in any waste by validated tion, decontamination/macroencapsulation of lead, laboratory decontamination methods, such as chemi- and reduction of chromium waste. cal decontamination or autoclave sterilization, before In spite of this capacity, many types of laboratory disposal. mixed waste have no commercial repository. No com- Special procedures are required in disposing of mercial mixed-waste disposal facilities exist for waste multihazardous waste that includes both hazardous contaminated with most toxic metals (such as mercury) chemicals and materials contaminated with microor-

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206 PRUDENT PRACTICES IN THE LABORATORY ganisms that are potentially pathogenic. The purpose in such waste are typically low enough to be accepted of the special procedures is to prevent the release of by a local treatment works. OSHA recommends that a infectious agents to the environment. The procedures separate sink be used exclusively for disposal of hu- involve decontaminating the mixed hazardous chemi- man blood, body fluids, and infectious waste. It may cal and biohazardous waste to eliminate the biohaz- be prudent to treat blood and body fluids with bleach ardous characteristics of the waste prior to disposal. (usually a 1:10 aqueous dilution of household bleach) Autoclaving and chemical decontamination are the prior to disposal in the sanitary sewer. Laboratory per- methods of choice for decontaminating biohazardous sonnel should take care to prevent personal exposure waste. Autoclaving volatile chemicals is not appropri- while waste is being discharged into the sewer. ate because this practice could cause the release of the chemical to the environment. 8.C.2.3 Disinfection and Autoclaving of Disposal is most difficult for the very small amount Contaminated Labware of chemical–biological waste that is EPA-regulated as chemically hazardous or contains a chemical, such as Contaminated labware may include cultures, stocks, lead, that is inappropriate for an animal or medical petri plates, and other disposable laboratory items waste incinerator. Disposal of tissue specimens pre- (e.g., gloves, pipettes, and tips). In many cases, the served in ethanol or another flammable solvent is also small quantities of infectious waste on labware can difficult. In most cases, storage of this waste is limited be disinfected safely with bleach or other chemical to 90 days and must be managed at an EPA-permitted disinfectant (e.g., by soaking overnight). Once disin- chemical waste facility. However, few chemical waste fected, the labware can be treated as a chemical waste. facilities are prepared to handle waste that is putres- Laboratory personnel must check with the state or cible, infectious, or biohazardous. regional EPA office to determine if a treatment permit is required for chemical disinfection of chemical–bio- logical waste. 8.C.2.1 Disposal of Chemically Contaminated Autoclaves can be used to steam-sterilize infectious Animal Tissue waste but should be tested routinely for efficacy. Au- Animal carcasses and tissues that contain a toxic toclaving does not require an EPA permit. Care must chemical may be the most prominent chemical–biologi- be taken because autoclaving of chemical–biological cal laboratory waste. Such waste includes biological waste at 120 to 130 °C may result in the volatilization specimens preserved in formalin and rodents that have or release of the chemical constituent. Additional waste been fed lead, mercury, or PCBs in toxicity studies. If containment may be needed to minimize chemical re- storage of such putrescible waste is necessary, refrig- leases, but it can interfere with steam penetration into eration is usually advisable. Infectious waste should be the waste load and sterilization. Before autoclaving, stored separately in a secure area. evaluate the waste to verify that the heat and pressure Incineration, which destroys potential infectious of autoclaving do not create unsafe conditions. agents, is the most appropriate disposal method for Autoclaving waste containing flammable liquids putrescible waste. Large research institutions are likely may result in a fire or explosion. Note also that steam to have an on-site animal incinerator. Medical waste sterilization of waste that contains bleach may harm incineration is also available through commercial an autoclave. To autoclave voluminous chemical– waste haulers. biological waste streams, it may be appropriate to (If animal or commercial incineration is unavailable, dedicate an autoclave room with ample ventilation and methods in section 8.C.3.3, below, may be adaptable to to restrict access. chemical–biological waste.) 8.C.2.4 Disposal of Chemically Contaminated 8.C.2.2 Sewer Disposal of Chemical–Biological Medical Waste and Sharps Liquids Laboratories that work with human blood must ad- Laboratories that manipulate infectious agents, here to OSHA’s Standard for Occupational Exposure blood, or body fluids may generate waste that is con- to Bloodborne Pathogens (29 CFR § 1910.1030), which taminated with these materials and toxic chemicals. In requires waste containment, marking, and labeling. most cases, blood and body fluids that contain toxic The OSHA standard also regulates waste disposal from chemicals can be disposed of safely in a sanitary sewer, laboratories that manipulate HIV or HBV. In general, which is designed to accept biological waste. Approval such waste that has chemical contamination can be for such disposal should be requested from the local incinerated with other medical waste. wastewater treatment works. Chemical concentrations Waste hypodermic needles and other “sharps” (e.g.,

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207 MANAGEMENT OF WASTE scalpels and razor blades) need to be contained in a • Risk associated with the waste should be assessed. puncture-resistant waste collection container. Sharps It may be prudent to decontaminate highly bio- should be destroyed by incineration or by grinding hazardous agents first to minimize handling risks. as part of the disinfection treatment. Incineration of Appropriate containment, handling, and storage chemical- or drug-contaminated needles in a medical precautions should be taken prior to treatment. waste incinerator is appropriate if the waste is not an • Radioactive–biological waste containing short- EPA-regulated chemical waste and if the chemical’s half-life radionuclides can be held for decay. After toxicity or contamination is low. Needles and other decay-in-storage, most USNRC licenses allow sharps that are contaminated with toxic chemicals and the waste to be managed as biological waste. If infectious agents or blood can be autoclaved or dis- the waste supports the growth of an infectious infected on-site (see the precautions above), and then agent that it contains, storage should be in a managed as a chemical waste. The waste container’s freezer to prevent the waste’s infectious load from biohazard symbol and markings should be defaced increasing. after autoclaving or disinfection to indicate that the • Refrigerated storage facilities or other preserva- waste has been sterilized. Noninfectious needles and tion methods are necessary for putrescible waste. sharps with high chemical toxicity or contamination are accepted by chemical incinerators. 8.C.3.1 Off-Site Management of Low-Level Some biomedical research generates materials con- Radioactive Waste taminated with blood and cytotoxic antineoplastic drugs or other highly potent drugs. Incineration of Many laboratories do not have an on-site incinerator these materials as medical waste is appropriate. In for radioactive–biological waste. Communities tend some cases, chemical disinfection and treatment can to oppose waste incinerators, and on-site incineration be combined to destroy both infectious agents and the is prohibitively costly for some radioactive–biological drug. Note that unemptied source containers of some waste generators. Even institutions that have incinera- drugs are EPA-listed hazardous waste and must be tors must usually rely on off-site disposal for some of managed as a regulated chemical waste. their radioactive waste. For radioactive putrescible waste, off-site disposal requires special packaging, storage, and transport considerations. 8.C.2.5 Minimization Methods for Chemical– Biological Waste 8.C.3.2 Disposal of Radioactive Animal Carcasses Waste minimization methods used for chemical and Tissue waste can be used to reduce or eliminate the chemical hazard of chemical–biological waste. Some laborato- Waste radioactive animal carcasses and tissue gen- ries that generate biohazardous waste have replaced erated from biomedical research typically pose no disposable items with reusable supplies, which are significant infectious hazard, but they are putrescible. disinfected between uses. USNRC regulations allow animal carcasses and tissue with less than 1.85 kBq/g of 3H or 14C to be disposed of For biological waste, waste minimization can be ac- complished best through careful source separation of without regard to radioactivity. Thus animal carcasses biological waste from other waste streams. When state and tissue below this limit need not be managed as a guidelines for defining infectious waste do not exist, it radioactive–biological waste but only as a biological is important for laboratories to define carefully those waste. biological wastes that can be disposed of safely as non- Animal tissue with higher levels of activity or other infectious within the framework of the CDC and NIH radionuclides must be managed as a radioactive waste. guidelines (HHS/CDC/NIH, 2007a). Training workers As with all putrescible waste, waste should be refriger- to identify and separate biological waste will prevent ated, frozen, or otherwise preserved during accumula- its inadvertent mixing with other waste streams and tion, transport, and storage. normal trash. Although on-site incineration is the preferred method of managing radioactive animal carcasses and tissue, several alternatives exist. Alkaline digestion of 8.C.3 Radioactive–Biological Waste animal carcasses containing 3H, 14C, and formalde- The management of radioactive–biological labora- hyde, followed by neutralization, results in an aque- tory waste can be difficult because of limited on- and ous radioactive stream that can usually be disposed of off-site disposal options. Basic principles for the man- in the sanitary sewer. The process uses 1 M potassium agement of radioactive–biological waste include the hydroxide at 300 °C and pressures up to 150 psi. Com- following: mercial units are available for this process. Radioac-

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208 PRUDENT PRACTICES IN THE LABORATORY tive animal carcasses may be accepted at a LLRW site 8.C.3.4 Sewer Disposal of Radioactive–Biological when packed in lime. Liquids Some institutions grind radioactive animal tissue Radioactive blood, body fluids, and other sewer- for disposal in the sanitary sewer. USNRC requires compatible liquids may be disposed of in the sanitary that all such sewer-disposable waste be dispersible sewer if quantities are within USNRC license and treat- within the liquid effluent. Preventing contamination ment work limits. Precautions must be taken to prevent and exposure of waste handlers to dust or particles is exposure of waste handlers. OSHA recommends that an important safety measure in this operation. disposal of human blood and body fluids be done in a Autoclaving of infectious animal carcasses is difficult dedicated sink. because of the waste’s high heat capacity and poor heat conductivity, and often unproductive because treated 8.C.4 Chemical–Radioactive–Biological waste remains putrescible. Waste Chemical–radioactive–biological laboratory waste 8.C.3.3 Disposal of Radioactive–Biological is the most difficult multihazardous waste to manage. Contaminated Labware The strategies for managing the various other types of Radioactive–biological contaminated labware (e.g., multihazardous waste described above are generally gloves and disposable laboratory articles) is generated applicable to chemical–radioactive–biological waste. from biomedical research using radioactive materials For example, toxicological research sometimes gener- with infectious agents, blood, and body fluids. On-site ates animal tissue that contains a radioactively labeled incineration, autoclaving, and off-site disposal are the toxic chemical. However, the chemical toxicity of such management options for this waste. Chemical decon- waste is commonly inconsequential, both legally and tamination (e.g., soaking in bleach) may be appropriate in relation to the waste’s other characteristics. It could if it can be done without risking personal exposure, be appropriate to dispose of such animal tissue as a increasing waste volumes, or creating a waste that is radioactive–biological waste, without regard to its low difficult to handle (e.g., wet waste). After disinfection, toxic chemical content. radioactive–biological waste can be managed as radio- Reduction or elimination of one of the waste hazards active waste. through waste management methods is often an effi- Infectious waste and sharps containers that contain cient first step. Decay-in-storage is a simple, low-cost radionuclides can be autoclaved safely if the following way to reduce the radioactivity hazard of a waste with precautions are satisfied: short-lived radionuclides. After decay, most USNRC licenses allow the waste to be managed as a chemi- • Monitor the air emissions of a test load to deter- cal–biological waste. Similarly, the use of a biological mine if the release of radioactive material is in decontaminate can reduce a chemical–radioactive– compliance with USNRC license limits. biological waste to a chemical–radioactive waste. • Wipe-test the autoclave interior for surface con- Autoclaves are readily available to most laboratories tamination regularly. for destruction of infectious agents. Autoclaving or • For ongoing treatment of this waste, dedicate an disinfection makes sense when any of the waste’s autoclave or autoclave room for this purpose. The characteristics (e.g., nutrient value) could support the room should have ample ventilation. growth of an infectious agent it contains and thus could • Restrict access during autoclaving. increase the waste’s risk. • Test the autoclave efficacy regularly using biologi- Certain waste treatments reduce multiple hazards in cal and chemical indicators. one step. For example, incineration can destroy oxidiz- able organic chemicals and infectious agents, waste Radioactive needles contaminated with infectious feed rates can be controlled to meet emission limits agents or blood should be autoclaved as described for volatile radionuclides, and radioactive ash can be above, and then incinerated on-site or shipped to a disposed of as a dry radioactive waste. Likewise, some LLRW site. To prevent injuries, it is important that chemical treatment methods (e.g., those using bleach) hypodermic needles and other sharps be kept in waste both oxidize toxic chemicals and disinfect biological containers that are puncture-resistant, leakproof, and hazards. Such treatment could convert a chemical–ra- closable from the point of discard through ultimate dioactive–biological waste to a radioactive waste. The disposal. To prevent generation of radioactive aerosols, ultraviolet peroxidation treatment method may well destruction of needles by grinding or a similar means demonstrate this capability. is not recommended.

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209 MANAGEMENT OF WASTE 8.D PROCEDURES FOR THE LABORATORY- 8.D.1 Treatment of Acids and Bases SCALE TREATMENT OF SURPLUS Neutralization of acids and bases (corrosives) is AND WASTE CHEMICALS generally exempt from a RCRA treatment permit. As described above in section 8.B.5, there are many However, because the products of the reaction are of- good reasons to perform in-laboratory-scale hazard ten disposed of in the sanitary sewer, it is important to reduction procedures. The pros and cons of many other ensure that hazardous waste such as toxic metal ions waste management methods are discussed earlier in is not a part of the effluent. this book (see Chapter 5, section 5.B, and Chapter 6, In most laboratories, both waste acids and waste section 6.B). The small-scale treatment, hazard reduc- bases are generated, and so it is most economical to col- tion procedures, and deactivation of products (and lect them separately and then neutralize one with the byproducts) as part of the experiment plan make sense other. If additional acid or base is required, sulfuric or for certain wastes and certain situations at the level of hydrochloric acid and sodium or magnesium hydrox- the actual generator, the trained laboratory personnel. ide, respectively, can be used. Beware that unless there is a significant reduction in Safety must be carefully considered before beginning risk by such action, there may be little benefit in carry- any work. If the acid or base is highly concentrated, it ing out a procedure that will simply produce another is prudent to first dilute it with cold water (adding the kind of waste with similar risks and challenges for acid or base to the water) to a concentration below 10%. disposal. Section 8.B.6 describes when federal law al- Then the acid and base are mixed, and the additional lows treatment of hazardous waste without permit. To water is slowly added when necessary to cool and recap, they are dilute the neutralized product. The concentration of neutral salts disposed of in the sanitary sewer should • In certain states small-scale treatment is allowed generally be below 1%. within a laboratory, sometimes as part of a permit- by-rule allowance. Be sure to check with your 8.D.2 Treatment of Other Chemicals state regulators. • Treatment in an accumulation container is al- The procedures listed below are for general use at lowed. the laboratory scale. Additional procedures can be found in the earlier editions of this book1 and other • Elementary neutralization (see 8.D.1, below); the mixing of acidic and alkaline waste to form a salt books listed on the accompanying CD. See Tables solution, has long been encouraged as long as 8.2 and 8.3 for a list of types of chemicals that have safety considerations are addressed. In particular, known treatment methods. Specific procedures for dilute solutions should be used to avoid rapid laboratory treatment are increasingly being included heat generation. in the experimental sections of chemical journals and • Treatment is allowed as part of an experiment (or in publications such as Organic Syntheses and Inorganic the last step) before it becomes a waste. Treatment Syntheses. of experimental byproducts assumes the material Safety must be the first consideration before under- has not been declared a waste or handled in a taking any of the procedures suggested. Procedures wastelike manner. Such treatment cannot be per- presented in this book are intended to be carried out formed anywhere other than the location where only by, or under the direct supervision of, a trained sci- the byproduct was generated. entist or technologist who understands the chemistry and hazards involved. Appropriate personal protection An explanation of the federal allowance to treat should be used. (See Chapter 7, section 7.F, for informa- waste in an accumulation container has been pub- tion on protective equipment and Chapter 6 for more lished in the Federal Register (1986). For this allowance, information about working with chemicals.) With the the container must be kept closed except when adding exception of neutralization, procedures are generally or removing waste, and all standard time limits for intended for application only in small quantities, that accumulation and container management apply. De- is, not more than a few hundred grams. Because risks pending on the final disposition of treatment byprod- tend to increase exponentially with scale, larger quantities ucts, federal Land Disposal Restrictions (40 CFR 268) should be treated only in small batches unless a qualified treatability standards may apply. chemist has demonstrated that the procedure can be scaled To ensure compliance, be sure to check local and state regulations that may apply, and seek a legal review if 1Prudent Practices for Disposal of Chemicals from Laboratories (NRC, 1983); Prudent Practices in the Laboratory: Handling and Disposal of any clarification is needed. Chemicals (NRC, 1995).

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210 PRUDENT PRACTICES IN THE LABORATORY Classes and Functional Groupings of Classes and Functional Groupings of TABLE 8.2 TABLE 8.3 Organic Chemicals for Which There Inorganic Chemicals for Which There Are Existing Treatment Methods Are Existing Treatment Methods Aldehydes Hydroperoxides Inorganic Peroxides and Alkali Metals Hydroperoxides Amines Peroxides Anhydrides Sulfides Bromates Iodates Halides Thiols (mercaptans) Cations (precipitation to their Metal azides hydroxides) Chemicals in which neither the Metal catalysts cation nor the anion presents a significant hazard up safely. The generator must ensure that the procedure Chlorates Metal hydrides eliminates the regulated hazard before the products are Chromates Molybdates disposed of as nonhazardous waste. In addition, if the Halides and acid halides of Periodates nonmetals procedure suggests disposal of the product into the Hypochlorites Permanganates sanitary sewer, this strategy must comply with local Inorganic cyanides Persulfates regulations. Inorganic ions Water-reactive metal halides