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1
Introduction, Overview, and
Recommendations
A. INTRODUCTION
This book is about the safe handling and disposal
of hazardous biological materials in the laboratory.
These materials consist of infectious agents, per se,
as well as substances actually or potentially contami-
nated with them.
A large number of laboratory workers handle such
materials as part of their daily routine. The number
has been estimated to be about 500,000 in the United
States, but that number is probably a gross underesti-
mate. The persons at risk are primarily the labora-
tory workers themselves, but the risks may extend to
others: students, custodial and maintenance workers
who must enter laboratories, handlers of shipped
materials, sanitation workers, and all who work in or
pass through building areas adjacent to the labora-
tory.
For the purposes of this book, the term "risk"
refers to the probability of acquiring an occupa-
tional infection, rather than to the severity of the
resulting disease. Such risk is actually much lower
than it is popularly perceived to be: the great major-
ity of organisms handled in the laboratory are either
not known to be hazardous or are of minimal poten-
tial hazard to laboratory personnel; in any case the
risk of exposure can be reduced to a very low level
by the use of the simple, prudent practices described
in this book. Furthermore, there is little or no risk to
the community at large: disease outbreaks in the
United States attributable to the escape of infectious
agents, either from laboratories or from waste dis-
posal sites, have been extremely rare.
The general concepts set forth in this book apply
to many Apes of laboratories: academic, industrial,
and governmental research laboratories; hospital, phy
sicians', veterinanans', and dentists' laboratories;
teaching laboratories; blood banks; and analytical
laboratories that handle potentially infectious materi-
als (e.g., clinical, diagnostic, and food laboratories).
We have included a section on biosafety in large-
scale production facilities, because laboratory work-
ers are often involved in the scale-up of benchtop
operations to the pilot plant level.
We have restricted ourselves to agents infectious
to humans: strictly animal and plant pathogens are
not addressed, although many of the practices rec-
ommended here are useful in the prevention of their
spread. We deal only briefly with the hazards associ-
ated with biological products (e.g., toxins and immu-
noactive materials), and we have chosen not to in-
clude the subject of recombinant DNA, given its
extensive coverage elsewhere [134,136] and the fact
that the hazard presented by an organism is not re-
lated to the use of recombinant technology in its
production but rather to the relative pathogenicity of
the donor organism, the nature of the vector, and the
hardiness of the recipient (host) organism. We do
not deal in this book with problems specific to hospi-
tal wards, to nosocomial infections, or to environ-
mental situations such as the presence of legionellas
in water tanks.
This book is designed to serve as an introductory
guide to biological safety in the laboratory; the prin-
ciples and practices described, however, are general
ones, and the readers must decide how best to apply
them in their own circumstances. Specific applica-
tions will vary with such factors as the design of the
local facility and equipment, the procedures in use,
the nature of the potential exposure, and the workers'
susceptibility.
Our text is addressed to all who are responsible
1
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2
for the safety of others, including the chief executive
officer of the institution, departmental chairpersons
and managers, project directors, and laboratory su-
pervisors; it is also addressed to the individual labo-
ratory workers, who share the responsibility for their
own safety as well as the safety of those around
them.
Although we have tried to be comprehensive in
our treatment of the general principles of biological
safety in the laboratory, we have dealt only briefly
with specific practices that are fully treated else-
where. A list of pertinent references is provided, and
the reader is urged to consult them for a more com-
plete treatment of the subject. In particular, labora-
tory workers who come into contact with human
blood, body fluids, or tissue should pay special atten-
tion to the practices described in the proposed guide-
lines on "Protection of Laboratory Workers from
Infectious Disease Transmitted by Blood and Tis-
sues," published by the National Committee for Clini-
cal Laboratory Standards [901, and the Centers for
Disease Control publication, "Recommendations for
Prevention of HIV Transmission in Health-Care
Workers" [341.
Finally, we call the reader's attention to Appen-
dix A, which reprints in its entirety the Centers for
Disease Control (CDC)/National Institutes of Health
(NIH) publication entitled Biosafety in Microbiologi-
cal and Biomedical Laboratories, published in 1984;
Appendix B. the 1988 "Agent Summary Statement
for Human Immunodeficiency Viruses (HIVs)," the
etiologic agent of AIDS; and Appendix C, "Recom-
mendations for Prevention of HIV Transmission in
Health-Care Settings" from the Morbidity and Mor-
tality Weekly Report of the CDC. Together, these
documents provide guidance for the handling of most
infectious agents that pose significant risks in the
laboratory.
B. OVERVIEW
The remainder of this book is divided into four
chapters: Chapter 2 deals with the epidemiology of
laboratory-acquired infections; Chapter 3 with the
safe handling of infectious materials; Chapter 4 with
the safe disposal of infectious materials; and, Chap-
ter 5 with safety management. Following is a brief
overview of these chapters.
BIOSAFETY IN THE LABORATORY
Chapter 2. Descriptive Epidemiology of
Occupational Infections of Laboratory
Workers
To determine the rate of occupationally related
infections among laboratory workers, it is necessary
to know both the number of actual infections over a
given period of time and the number of persons who
are at risk. As discussed in this chapter, neither
figure is known; however, the data presented here
give some qualitative appreciation of risk and group
pathogens into high-risk and low-risk categories.
Thus, from the beginning of the twentieth century
until the present, the `'top five" (highest-risk) organ-
isms handled in laboratories have been the agents of
brucellosis, Q fever, typhoid fever, viral hepatitis,
and tuberculosis; organisms in the category of lowest
risk have included rabies virus, Creutzfeldt-Jakob
agent, Vibrio cholerae, Clostridium tetani, C. botu-
linum, and HIV. These rank orders are changing,
however, with changes in the prevalence of the mi-
croorganisms in the general population, and in the
frequency with which they are handled in the labora-
tory.
Chapter 3. Safe Handling of Infectious
Agents
The material in this chapter falls into two catego-
ries. The first category, comprising Sections A through
E, deals with the biological materials that may be
hazardous:
pathogenic microorganisms;
organisms posing special risks;
vertebrate animals and insects;
· cell cultures; and
· necropsy and surgical specimens.
In each case, there is a discussion of the special
precautions that should be taken in handling the or-
ganism or the infectious material.
The second category, comprising Sections F
through K, deals with the general procedures and
equipment that make it possible to handle biohaz-
ardous materials safely. Section F. "Good Labora-
tory Practices," lists seven basic rules of biosafety;
these are reprinted in the set of recommendations at
the end of this chapter (Section C.3~.
The same good laboratory practices are recom-
mended for persons working with plant-specific pa
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INTRODUCTION, OVERVIEW, AND RECOAIMENDATIONS
thogens, animal-specific pathogens, and other viable
microorganisms not associated with human disease.
The remaining sections deal with the following
topics:
· transportation and shipment of biomedical
materials,
labeling of specimens,
prevention of aerosol and droplet generation,
containment equipment,
personnel protective equipment,
biosafety in large-scale production, and
small-volume clinical laboratories.
Once again it must be emphasized that the prin-
ciples and practices described in this book are general
ones, and the readers must decide how best to apply
them under their own special circumstances.
Chapter 4. Safe Disposal of Infectious
Laboratory Waste
In the United States, biological laboratory waste
presents an occupational, rather than a public health,
hazard. For the reasons discussed in this chapter,
outbreaks of infectious disease attributable to such
waste have not occurred or are extremely rare as a
result of highly effective sanitation measures. These
measures include physical barriers in the form of
well-constructed drains, sewers, and refuse contain-
ers, along with properly constructed and operated
sewage treatment plants, sanitary landfills, and mu-
nicipal incinerators. Thus the public's health is pro-
tected even if infectious waste is introduced untreated
into a municipal sewage treatment facility, a sanitary
landfill, or a solid waste incinerator.
The potential for exposure to infectious agents
does exist, however, for workers who generate, handle,
and process biological laboratory waste. These work-
ers can be protected effectively from exposure by a
number of simple procedures, of which the principal
ones are as follows:
segregation of infectious from noninfectious
waste;
· on-site treatment, including chemical decon-
tamination, use of the steam autoclave or incinera-
tor, and appropriate packaging for transport; and
· personal protection, in the form of protective
clothing, gloves, and handwashing.
Mixed waste, which contains infectious agents and
radioactive or chemically hazardous materials, re-
quires special processing.
The primary responsibility for the safe handling
and disposal of infectious waste lies with the labora-
tory that generates the waste, but waste haulers and
managers of treatment facilities and sanitary landfills
also share in the responsibility.
Chapter 5. Safety Management
This chapter outlines the administrative responsi-
bilities associated with biosafety in the laboratory
and recommends some general practices for dealing
with them. As described here, an effective safety
management program includes the following:
clear goals,
well-defined responsibilities,
mandatory safety rules,
written safety plans,
safety committees,
effective safety communications,
emergency preparedness, and
auditing of laboratory operations.
Also, as discussed in this chapter, every institu-
iion or laboratory should have a biosafety manual
that addresses the following topics:
· policy and goals,
· safety organization,
· medical programs,
· laboratory procedures for labeling and han-
dling specimens, preventing aerosol and droplet
generation, properly using needles, discarding
materials, steam autoclaving and disinfecting,
cleaning-up of spills, using and maintaining safety
cabinets, controlling insects and other pests, and
working with animals,
· safety equipment,
· waste disposal, and
· emergencies.
The above outlines for a safety plan and a bio-
safety manual can serve as a rough checklist for
those who are responsible for day-to-day safety in
He laboratory.
Chapter 5 also deals with the proper design, op-
eration and maintenance of facilities; safety training;
risk assessment; record keeping; medical surveillance;
and regulation and accreditation.
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C. RECOMMENDATIONS
On the basis of the considerations discussed in
this report, the committee recommends He following
actions; they are presented in the order in which they
appear in the text
1. Immunization
Employees handling clinical specimens or infec-
tious agents should be immunized with the vaccines
required for admission to elementary school, or have
documented immunity. Personnel working with
blood, serum, or other body fluids should be immu-
nized against hepatitis B. Immunizations with other
available vaccines, including experimental products,
should be considered on an individual basis. (See
Chapter 3, Sections B and E, and Chapter 5, Section
D.)
_
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BIOSAFETY IN THE LA~OMTORY
2. Serum Bank
The establishment of a serum bank should be
considered for employees, depending upon the job
situation and management policy. Specimens should
be collected at the time of employment and others
taken periodically Hereafter. (See Chapter 3, Sec-
tion B. and Chaps 5, Section D.)
3. AvoWing Exposure to Infectious Agents
The following seven laboratory practices should
be observed at all times.
.
Do not mouth pipette (Figure 1.1).
· Manipulate infectious fluids carefully to
avoid spills and the production of aerosols and
droplets (Figure 1.2~.
· Restrict the use of needles and syringes to
those procedures for which there are no alterna
lIGURE 1.1 Do not mouth pipette. Regrettably, many laboratory workers have been taught to pipette by moldy, a practice
that has led to a significant number of laboratory-acquired infections. These individuals should be required to give up the old
practice and to learn to use the pipetiing aids that are now available for any application. Any device requiring mouth suction
should be considered unsafe and inappropriate for use in the biological laboratory. Courtesy, John H. Richardson.
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INTRODUCTION, OVERVIEW, AND RECOMMENDATIONS
fives; use needles, syringes, and other "sharps"
carefully to avoid self-inoculation; and dispose of
"sharps" in leak- and puncture-resistant contain-
ers.
· Use protective Laboratory coats and gloves.
· Wash hands following all laboratory activi-
ties, following the removal of gloves, and immedi-
ately following contact with infectious materials
(Figure 13~.
· Decontaminate work surfaces before and
after use, and immediateb after spills (Figure 1.4~.
· Do not eat, drink, store foods, or smoke in
the Laboratory.
5
In working with specific etiologic agents, the NIH/
CDC guidelines reprinted in Appendix A should be
followed. (See Chapter 3, Section F.)
4. Transportation and Shipment of
Specimens
All shipments of biological materials, cell cul-
tures, and infectious agents should be made in accor-
dance with the applicable regulations of the U.S.
Public Health Service, He U.S. Department of Trans-
portation, He U.S. Department of Agriculture, and
the U.S. Postal Service. (See Chapter 3, Section G.)
FIGURE 1~2 Manipulate infectious fluids carefully to
avoid spills end the production of aerosols end droplets. This
photomicrograph shows the copious production of aerosols
and droplets when the last drop in a pipette is blown out.
Enough material can be aerosolized by such practices to
create an infectious dose of some agents. Courtesy, Nation-
al Institutes of Health
FIGURE 13 Wash hands following all laboratory activi-
ties, following He removal of gloves, and immediately
following contact with infectious agents. Courtesy, John H.
Richardson.
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BIOSAFETY IN THE LABORATORY
FIGURE 1.4 Decontaminate work surfaces before and after use, and immediately after spills. Courtesy, National Institutes
of Heals.
5. Labeling of Specimens
All clinical specimens should be regarded as in-
fectious and handled accordingly, whether or not
they bear special hazard warning labels. (See Chap-
ter 3, Section H.)
6. Biosafety In Large-Scale Production
The principles and practices described for the
control of biohazards in benchtop operations should
be applied to the propagation of microorganisms in
large-scale production processes. (See Chapter 3,
Section K.)
7. Safe Disposal of Infectious Laboratory
Waste
Just as with chemically hazardous waste, the gen-
erators of infectious laboratory waste have the re
sponsibility to ensure that their waste is safely handled
from "cradle to grave." Treatment and disposal of
infectious waste by conventional methods such as
solid waste incineration, sanitary landfills, and sew-
age treatment plants are adequate to protect He pub-
lic's health. Th,e risk of occupationally acquired
illness, however, is present for workers who handle
infectious waste. The following recommendations
are presented to reduce this risk:
· institutions should establish a waste man-
agement plan for the collection, segregation, con-
tainment, treatment, and disposal of infectious
waste;
· workers involved in the handling of infec-
tious waste should be informed of the potential
hazard and should be proficient in the use of the
necessary safeguards for their own protection;
· incineration, the method of choice for the
decontamination of infectious waste, should be
used whenever possible; and
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INTRODUCTION, OVERVIEW, AND RECOMMENDATIONS
the principles of containment should be ap-
plied to all steps in the chain of handling infec-
tious waste, from generation to disposal. (See
Chapter 4.)
8. Administrative Organization and
Responsibility
The institution should have an overall safety,
occupational health, and environmental protection
program that includes biosafety in the laboratory and
provides for compliance with federal, state, and local
government regulations. The program should pro-
vide safety training for all laboratory, maintenance,
and housekeeping personnel, for members of the
medical staff, and for students who will come into
contact with infectious materials in the course of
their studies.
The responsibility for safety in a department or
other administrative unit lies with its chairperson or
supervisor. However, all individuals must accept
responsibility for carrying out their work in a way
that protects them and their fellow workers. Respon-
sibility for safety must be clearly defined.
There should be a biosafety manual that sets forth
the following: safety policy, goals, and organization;
medical program; laboratory procedures; safety equip-
ment; waste disposal methods; and emergency pro-
cedures. (See Chapters 4 and 5.)
9. Facilities
In order to provide an optimum environment for
biohazardous work, facilities must be properly de-
signed, constructed, validated, maintained, and used.
Plans should be reviewed by the appropriate safety
officer before construction begins, and again after
7
the building has been completed but before work
with infectious materials begins. Final construction
(as-built) drawings should always be available for
future reference. (See Chapter 5, Section B.)
10. Medical Program
Laboratories should have a medical program that
is targeted to the potential risks and hazards of its op-
erations. There should be a regular analysis of the
collected data. Some employees may be found to
have personal health conditions that place them at
increased risk when performing certain laboratory
functions. In such cases, a careful assessment should
be made of the potential for exposure; if the exposure
cannot be eliminated or reduced, consideration should
be given to changing jobs or tasks. Employees should
be informed completely about the potential risks and,
to the extent possible, should be involved in the
decision-making process. (See Chapter 5, Section
D.)
11. Emergencies
Every laboratory organization has the responsi-
bility to establish a specific emergency plan for its
facilities and to be equipped to implement it. The
plan should include the laboratory building as well as
individual laboratories. For the building, the plan
should include evacuation routes, shelter areas, medi-
cal treatment, and procedures for reporting accidents
and emergencies. It should be reinforced by drills
and simulated emergencies, and should include liai-
son with local emergency groups as well as commu-
nity officials. For individual laboratories, the plan
should cover such events as spills, fires, equipment
failure, and accidents. (See Chapter 5, Section E.)
Representative terms from entire chapter:
laboratory workers
