Proper Disposal of Chemicals

Hazardous Waste Collection and Disposal. It is not too much of an exaggeration to say that virtually everything except distilled water is considered to be hazardous waste, and must be handled and disposed of according to EPA (Environmental Protection Agency) guidelines. Hazardous waste disposal is overseen by Mr. David Messier (email: dmessier@wpi.edu), who supplies labels for hazardous waste containers and picks up full containers by appointment. With few exceptions, reagents and solvents used by students must be collected in appropriate containers and disposed of via Dave Messier.

A few substances can still be disposed of in the sink drains, accompanied by a substantial water flush. These include

• Aqueous sodium chloride
• Aqueous sodium sulfate
• Aqueous sodium carbonate or sodium hydrogen carbonate
• Aqueous sodium phosphate, sodium hydrogen phosphate, or sodium dihydrogen phosphate
• Dilute aqueous sodium acetate
• Dilute aqueous hydrochloric acid (6 M or less)
• Dilute aqueous sulfuric acid (6 M or less)
• Dilute aqueous nitric acid (6 M or less)
• Dilute aqueous sodium hydroxide (6 M or less)
• Dilute aqueous potassium hydroxide (6 M or less)
• Dilute aqueous ammonia
• Dilute aqueous phosphoric acid (6 M or less)
• Dilute aqueous acetic acid (6 M or less)

All other materials must be collected in bottles with official hazardous waste labels. Labels must be properly filled out with the names and weight percentages of the component materials, and toxicity, corrosive ability, potential flammability, and potential reactivity must be indicated. OMISSION OF ANY OF THIS INFORMATION IS A VIOLATION OF EPA POLICY.

Three categories of waste will commonly occur in the general chemistry labs:

1. Non-halogenated organic solvents. The halogens are the elements, fluorine, chlorine, bromine, and iodine. Organic liquids NOT containing any of these elements are called non-halogenated organic solvents. They include but are not limited to
   • acetone
   • ethanol
   • methanol
   • isopropanol
   • benzene
   • toluene
   • tetrahydrofuran
   • acetonitrile
   • glacial acetic acid
2. Halogenated organic solvents. These are organic liquids that contain one or more of the elements fluorine, chlorine, bromine, and iodine in their chemical structures. They include but are not limited to
   • chloroform
   • dichloromethane
   • carbon tetrachloride
   • methyl iodide
   • tetrachloroethane
   • dichlorethane
   • freons
3. "Heavy Metals". These include the transition metals and the heavier elements of groups 13, 14, and 15. Common "heavy" metals, which usually occur in cationic form, are
   • aluminum
   • gallium
   • indium
   • thallium (very poisonous)
   • tin
   • lead (very poisonous)
   • chromium (carcinogen in some forms)
   • manganese
   • iron
   • cobalt
   • nickel
   • copper
   • zinc
   • cadmium (very poisonous)
   • mercury (very poisonous)
   • uranium

When any of these three categories of substance is to be used in a general chemistry experiment, THERE MUST BE PROPERLY LABELLED AND SIZED WASTE CONTAINERS AVAILABLE IN ALL HOODS IN GH109/110. Students MUST properly dispose of these substances.