Civil Engineering

Waste Disposal

All chemical waste disposal is carried out by the Department of Environmental Health and Safety; sinks and garbage cans are not to be used for hazardous waste disposal. All hazardous waste must be segregated according to the procedures outlined below in Packaging and Identification of Hazardous Waste. The general procedure for disposing of waste chemicals is outlined below in Disposal Procedures Hazardous Chemicals.

Flammable liquids such as common organic solvents must be placed in solvent disposal cans (red with wide mouths and flame arrestor) which are identified as to point of origin. This waste should be collected in separate containers for Halogenated and Non-halogenated waste (<3% halogen content).

Containers which have been used to store chemicals, such as stock bottles, but which are empty may be disposed of with the normal garbage; these bottles should be washed and the labels defaced before they are placed in the garbage.

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Packaging and Identification of Hazardous Waste

The purpose of the following instructions is to prevent dangerous chemical reactions if there is an accident during transit.

  1. All chemicals must be packed in sturdy containers, using an inert packing material such as vermiculite.
  2. Chemicals must be taken from the laboratory by the user to the pick-up point. Disposal companies require that chemical wastes be identified as members of one of the following Chemical Code Groups:

Group A

  • Inorganic Acids
  • Elements and inorganic salts that do not liberate gaseous products when acidified.

Group B

  • Inorganic alkaline chemicals
  • Organic bases
  • Elements and inorganic salts which liberate gaseous products when acidified.

Group C

  • Solid organic compounds (excluding bases)

Group D

  • Organic liquids (excluding organic bases) NOTE: Separate containers must be used for halogenated and non- halogenated Group D liquids.

Group E

  • Inorganic oxidizing agents NOTE: Group E chemicals cannot be stored or transported with any other chemicals in a common container.

Group F

  • Pesticides

Group G

  • Shock sensitive materials
  • Organic oxidizing agents
  • Pressurized containers, gas cylinders
  • Materials that react violently with water
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Disposal Procedure Hazardous Chemicals

DEFACE all containers that have hazardous material warnings if they no longer contain hazardous materials.

SEGREGATE incompatible materials (see back of pink form).

SEPARATE unopened, unused chemicals from other material to be disposed.

LABEL the chemical name, contaminants (including levels when known), concentration (molarity, dilution factor, etc.), must appear on each individual bottle, bag, box or container of chemicals or by-product. To comply with transport regulations, an inventory must be attached to external packaging (pink forms are provided for your convenience).

COMPLETE and ACCURATE IDENTIFICATION of all materials is the single most important factor in providing safe, environmentally sound and cost- effective hazardous waste management.

UNKNOWNS can not be transported.

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Individual departments must bear all costs for analysis/identification when the identity of a material cannot be determined (with certainty) by the originating department.


  1. Solid Chemicals must be packed in cardboard boxes with an acceptable absorbent material such as vermiculite surrounding the individual containers (styrofoam chips are not acceptable as they are reactive and non-absorbent).
  2. Liquid Chemicals must be packaged as above, in their original shipping containers, or (if they are non-corrosive) in suitable non-breakable containers approved by E. H. & S.
  3. Flammable Liquids must be placed in Solvent Disposal cans (the red ones with the wide mouth). Cans must be clean, with an intact flame arrestor and labelled according to point of pickup. Non-flammable, non-corrosive liquid material may be mixed with flammable material provided that the materials are compatible.
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