All laboratories that use chemicals inevitably produce chemical waste that must be properly disposed of. It is crucial to minimize both the toxicity and the amount of chemical waste that is generated.

A waste management and reduction policy that conforms to State and local regulations should be established by the school or school district.

Several things that can be done to minimize hazards, waste generation, and control costs:

• Purchase chemicals in the smallest quantity needed.
• Use safer chemical substitutes/alternatives such as chemicals which have been determined to be less harmful or toxic (Table 1 contains examples).
• Use microscale experiments.
• Chemical experiments using smaller quantities of chemicals Recycle chemicals by performing cyclic experiments where one product of a reaction becomes the starting material of the following experiment.
• Consider detoxification or waste neutralization steps.
• Use interactive teaching software and demonstration videos in lieu of experiments that generate large amounts of chemical waste.
• Perform classroom demonstrations.
• Use preweighed or premeasured chemical packets such as chemcapsules that reduce bulk chemical disposal problems (no excess chemicals remain).

For information about the EPA’s Green Chemistry Program, which promotes the use of innovative technologies to reduce or eliminate the use or generation of hazardous substances, visit:

• www.epa.gov/greenchemistry/
• www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=greenchemistryinstitute/index.html

What is the Recommended Procedure for Chemical Disposal?

Any chemical discarded or intended to be discarded is chemical waste.

HAZARDOUS chemical waste as designated by the Environmental Protection Agency (EPA) or State authority is waste that presents a danger to human health and/or the environment.

According to EPA regulations, there are four characteristics that define a waste as hazardous:

• Ignitability
• Corrosivity
• Reactivity
• Toxicity

In addition, there are lists of hundreds of other chemicals that EPA has determined to be hazardous waste.

Because of particular differences within some States, consult your State or regional EPA office to determine whether waste is considered hazardous and the requirements for storage and disposal.

For chemical waste, it may be best to use a log book to contain detailed lists of materials in a container labeled "organic waste", for example.

Storing Chemical Waste

• Store all waste in containers that are in good condition and are compatible with their contents.
• Clearly and permanently label each container as to its contents and label as hazardous waste (refer section titled How Should Chemical Containers Be Labeled? for specific information).
• Store waste in a designated area away from normal laboratory operations and to prevent unauthorized access.
• Store waste bottles away from sinks and floor drains.
• Do not completely fill waste bottles; leave several inches of space at the top of each waste container.
• Cap all waste bottles.

Proper Disposal of Chemical Waste

The EPA has written a comprehensive set of regulations that govern the management of hazardous waste from the point of generation to ultimate disposal (www.epa.gov/epaoswer/osw/conserve/clusters/schools/index.htm)

Generators of hazardous waste are responsible for ensuring proper disposal of their hazardous waste and can incur liability for improper disposal of their hazardous waste.

Disposal Procedure

• Do not pour chemicals down the drain (unless authorized by local sewer authority).
• Do not treat hazardous waste on-site.
• Contact professional, licensed hazardous waste haulers/transporters that will ensure appropriate disposal.