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Procedures for Specific Hazardous Wastes

The fewer the number of chemicals associated with a waste, the more economical is the disposal method for that waste.  If this is not practical, the Safety Office should be consulted about which wastes can be combined safely.  Always separate incompatible materials! 

Procedures for individual waste streams:

Flammable solvents:
Non-halogenated solvents are sent to an incinerator or recycler and must be free of heavy metals and reactive materials, e.g. sodium metal.

Halogenated solvents should be separated from non-halogenated flammable solvents. Examples of halogenated solvents include methylene chloride, chloroform, and carbon tetrachloride.

Acids and Bases:
Segregate containers of acids and bases from one another in individual, compatible containers while accumulating as waste.  Acids and bases containing heavy metals must never be disposed to the sewer system.

Oils:
Oils are sent to a recycler.  Only trace quantities of oils associated with cleaning and washing operations should be released to the sanitary sewer.  Oil wastes from vacuum pumps, transformers, motors, etc., should be accumulated for pick-up.  Oily rags should be sent to a cleaning service.

Biocides:
Concentrated solutions are not to be released to the sanitary sewer.  Disposal is to be limited to one gallon of "working strength" solution per laboratory per day.  This applies primarily to germicides and occasional disposal of pesticides.  Chemicals which are persistent in the environment should be released only in trace quantities.

Sodium azide:
Solutions containing sodium azide, commonly used as a preservative in many in-vitro diagnostic products and with automatic blood cell counters, cannot be discharged to the sanitary sewer. The accumulation of lead and/or copper azide in the drain pipes can produce a potentially explosive situation.
Oxidizers:
Package oxidizers separately; store and accumulate away from organics including flammable materials. Oxidizers should never be stored or accumulated adjacent or proximate to any organic substances.

Compressed Gas Cylinders:
Disposal of non-returnable (i.e. lecture bottles) cylinders that are not empty can be very expensive, especially for reactive gases.  Make every effort to purchase form suppliers who have a cylinder return program.  Even if a cylinder seems empty, it cannot be discarded in the trash.  Always treat pressurized cylinders as waste and contact the Safety Office for disposal.

Unknowns:
Unlabeled and unidentified chemicals present a challenging, dangerous, and very costly disposal problem.  Exercise every precaution to avoid generating unknowns in the laboratory and ensure that all containers are properly labeled.  If you discover unknown chemicals, please contact the Safety Office.

Needles and Syringes: 
Never place needles or other sharps in the regular trash or the recycling bins. They must be accumulated in approved hard-walled containers.  Needles and syringes contaminated with infectious agents must be autoclaved or otherwise decontaminated before disposal.

Broken Glassware/Sharps: 
Place uncontaminated glassware and non-regulated sharp objects in a plastic bag within a cardboard box identified with a label indicating “Non-Hazardous Glass and Sharps Waste”. 

  • Without compromising your own safety, clean all glassware of residual chemicals before disposal.  If chemicals cannot be removed, label the box with the chemical name and contact the Safety Office for disposal.
  • Use an approved labeled container. Dispose of uncontaminated glass in a glass disposal box.
  • Do not overfill the container.  Keep boxes to 30 lbs. or less.  When full, tie bag, tape lid closed, and place in the hall for housekeepers to remove. 

Infectious and Radioactive Waste: 
There are additional waste guidelines for infectious or radioactive waste.  Contact the Safety Office for guidance in managing these waste streams.  

Container Labeling

All containers must be labeled with the words "Hazardous Waste" and include the following information:

  • The full chemical name (no formulas, abbreviations, or structures) of each component in the waste container.
  • The estimated percentage of each waste component in the container.
  • The accumulation start date when waste was first added to the container.
  • Indicate if the material is regular waste (used) or unused pure commercial product.
  • The total volume of waste in the container. This is very important information for inventory tracking.  To make disposal more cost effective, always choose an appropriate size and fill the container leaving 10% headspace to account for expansion.
  • The location and generator of the waste.

Waste Containers

Containers and lids must be in good condition and be chemically compatible with the waste inside the container.  Lab beakers, flasks, household containers (i.e. milk cartons) are not acceptable as waste containers.  Metal containers are not acceptable unless they are the original container for the chemical waste being managed.  Containers must have securely fitting lids, preferably the original lid for the container.  Do not use corks, stoppers, a watch glass, or parafilm. 

Containers must be kept closed.  Evaporation of waste is not a legal means of disposal!  Do not leave the funnel in the container as this does NOT constitute a lid, even if covered with a watch glass!  Waste containers must remain securely capped at all times, except: 

  • When adding, removing, or consolidating waste materials.
  • When venting of the container is necessary for either the proper operation of laboratory equipment (such as HPLC), or to prevent the dangerous buildup of extreme pressure that may result from a reaction between the wastes being added. In some cases, a vented container lid should be employed to prevent gas build-up.  For assistance in locating a vented lid for waste storage containers, contact the Safety Office.

Liquid Waste
Liquid wastes may be accumulated in glass reagent bottles compatible with the waste.  If you generate a large volume of liquid waste, consider a 5-gallon carboy for solvent accumulation.  Filled containers of liquids must have at least ten percent headspace to accommodate thermal expansion during transport and storage.  Store glass waste containers in rubber safety carriers, buckets, or similar containers to protect against breakage and spillage.  All waste containers holding 4 liters or less of liquid chemical waste, and all glass containers of liquid chemical waste stored on the floor, require secondary containment.

Solid Waste
Solid wastes may go into a double-lined cardboard box.  Liners must be 1.5 mil or greater polypropylene bags.  Do not use biohazard or radiation waste bags for solid waste accumulation, regular, labeled trash bags are preferred.  Tie and seal each bag individually.  Ethidium bromide-containing solid and semi-solid waste (e.g. used gels) should also be collected in double bags within cardboard boxes.  Collect liquid ethidium bromide waste in a carboy or bottle and manage accordingly.

Reactive Waste
Reactive chemicals must be disposed of in their original shipping containers, or in containers approved by the Safety Office.

Empty Chemical Containers
Empty glass containers can either be used for waste collection if compatible with the waste, or defaced (label erased & marked as empty) and put in the glass disposal box.  Keep glass boxes to 30 lbs. or less.  When full, tie bag, tape lid closed, and place in the hall for housekeepers to remove. 

Plastic containers can be recycled after the containers have been cleaned out of chemical, and the lid removed. 

*NOTE: If the container was used for a P-listed chemical, or other acutely toxic substance, it is collected for hazard waste disposal and labeled as such.

The most commonly cited violations of hazardous waste/material regulations include:

  • Open containers or lids not screwed on tightly.
  • Improper labeling (missing information) or lack of a label.
  • No secondary containment.
  • Waste storage accumulation area (trip hazards, blocking emergency equipment, etc.).

What may seem like a relatively minor violation can result in fines of several thousands of dollars per violation.  Observing the waste guidelines and reviewing the following questions with personnel on a regular basis can keep the University in compliance:

LIDS – Are all containers closed securely with proper lids?
LEAKS
– Are containers stored in secondary containment?
LABELS
– Are the containers properly labeled with chemical contents, type of hazard (flammable, corrosive, etc.), and accumulation start date?
LOCATION
– Is the storage area in compliance (no trip hazards, clear aisle space, warning signs, etc.)?

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