Office of Security, Safety and Risk Management

Chemical Hygiene Plan

A7.	CHEMICAL WASTE DISPOSAL In order to assure that minimal harm is done to people, other organisms and the environment from the disposal of waste laboratory chemicals, indiscriminate disposal by pouring them down the drain or adding them to mixed refuse for landfill burial is unacceptable. The following procedures should be followed in disposing of waste chemicals:
	1.	Whenever possible, spent solvents should be recovered and recycled by distillation or chromatographic purification for reuse.
	2.	Aqueous solutions of acids and bases should be neutralized before flushing down the drain with large volumes of water.
	3.	Solutions containing toxic heavy metals such as mercury, lead, chromium, silver, etc. should be precipitated and the metal recovered in solid form for subsequent disposal as a solid waste.
	4.	Fume hoods should not be used as a means of disposal of volatile chemicals.
	5.	Liquid organic wastes should be emptied into labeled plastic containers kept in vented metal cabinets in each laboratory. Waste containers should be labelled "polar", meaning alcohols, acids, amines and other compounds capable of forming hydrogen bonds, and "non-polar" meaning anything else including halogenated hydrocarbons. Liquid waste containers should be removed and replaced when full and safely stored for disposal by a licensed waste hauler.
	6.	Highly reactive wastes such as acid chlorides should be converted to a less reactive form before disposing in the waste containers.
	7.	Dry solid wastes should be stored in labelled plastic containers until removed by a licensed waste hauler. A running inventory should be maintained of each waste container's contents.
	8.	Old or unneeded chemical stocks should be removed from storage and disposed of at least annually.
	9.	Before a worker's employment in a laboratory ends, chemicals for which that person was responsible should be discarded or returned to storage.

Section B1