. "Appendix B: Laboratory Chemical Safety Summaries." Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. Washington, DC: The National Academies Press, 1995.
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Prudent Practices in the Laboratory: Handling and Disposal of Chemicals
Reactivity and Incompatibility
Highly explosive nitrogen halides will form in reactions with halogens, hypohalites, and similar compounds. Reaction with certain gold, mercury, and silver compounds may form explosive products. Violent reactions can occur with oxidizing agents such as chromium trioxide, hydrogen peroxide, nitric acid, chlorite, chlorate, and bromate salts. Exothermic and violent reactions may occur if concentrated ammonium hydroxide solution is mixed with strong acids, acidic metal and nonmetal halides, and oxyhalides.
Storage and Handling
Ammonium hydroxide should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C. All work with this substance should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and impermeable gloves should be worn at all times to prevent eye and skin contact. Containers should be tightly sealed to prevent escape of vapor and should be stored in a cool area separate from halogens, acids, and oxidizers. Containers stored in warm locations may build up dangerous internal pressures of ammonia gas.
Accident
In the event of skin contact, immediately wash with soap and water and remove contaminated clothing. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If ammonium hydroxide is ingested, obtain medical attention immediately. If large amounts of ammonia are inhaled, move the person to fresh air and seek medical attention at once.
In the event of a spill, soak up ammonium hydroxide with a spill pillow or absorbent material, place in an appropriate container, and dispose of properly. Alternatively, flood the spill with water to dilute the ammonia before cleanup. Boric, citric, and similar powdered acids are good granular neutralizing spill cleanup materials. Respiratory protection may be necessary in the event of a large spill or release in a confined area.
Disposal
In some localities, ammonium hydroxide may be disposed of down the drain after appropriate neutralization and dilution. In a fume hood, the concentrated solution should be diluted with water to about 4% concentration in a suitably large container, and neutralized with a nonoxidizing strong acid such as HCl. The resulting solution can be discharged to the sanitary sewer. If neutralization and drain disposal are not permitted, excess ammonium hydroxide and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines. For more information on disposal procedures, see Chapter 7 of this volume.