Step five: Check Washington state-only criteria

Determine if your waste is a Washington state-only persistent or toxic waste.

Washington toxic criteria

In addition to the federal toxic characteristic D List (in Step four), Washington toxic criteria wastes are regulated because testing shows they are lethal to fish or animals. Highly toxic chemicals will cause mortality at low concentrations.

Washington toxic criteria wastes are coded WT01 or WT02, depending on the concentration of the waste's toxic constituents. WT01 wastes have a 2.2 quantity exclusion limit (QEL) — learn more about QEL and generator category. Details about WT01 and WT02 wastes are in the regulations (WAC 173-303-100).

You can test for this using a bioassay, which means a laboratory will use a sample of your waste to determine if it kills fish or other animals at a certain concentration.

Alternatively, you may be able to use a toxicity database to determine if it’s a Washington state-only toxic. These databases show the results from previous tests for specific chemicals on animals. You’ll need to know the concentration of specific chemicals in your waste. If you use information from such databases, you must use the most conservative results. If data are available for more than one test endpoint (that is, fish, oral-rat, inhalation-rat, or dermal-rabbit), the value with the highest toxicity must be used. Results from tests on salmonids (the family of fish that includes salmon, trout, and other fish) must be used before tests on minnows. And results from minnows must be used before tests on other animals.

Example databases:

Once you get sample test results from a database, you need to use the equation in the regulations (WAC 173-303-100) to calculate the equivalent concentration to compare it to the Toxic Category Table in the regulations.

Biological Testing Methods for the Designation of Dangerous Waste describes animal testing requirements. For example, tests on fish must be conducted for at least 24 hours.

Washington persistence criteria

Wastes contain chemicals that are slow to break down. They linger in the environment and can accumulate in living tissue. There are two groups of Washington persistent wastes in the Dangerous Waste Regulations: polycyclic aromatic hydrocarbons and halogenated organic compounds.

Polycyclic aromatic hydrocarbons (PAHs)

Twenty hazardous chemicals are identified as PAHs in the regulations (WAC 173-303-040). These are hydrogen molecules fused with two or more benzene rings. Wastes with more than 1 percent PAHs have the waste code WP03 and are considered Extremely Hazardous Waste (EHW).

Halogenated organic compounds (HOCs)

HOCs are any organic (carbon-based) compound with at least one atom of bromine, chlorine, fluorine, or iodine bonded directly to a carbon atom. For example, dry cleaning perchloroethylene solvent is a common HOC. HOCs are measured in parts per million (ppm). HOC wastes with total concentration greater than 100 ppm (0.01-1.0 percent) have a WP02 waste code. Wastes greater than 1.0 percent HOC content (10,000 ppm) are considered Extremely Hazardous Waste (EHW) and have a WP01 waste code.

Check your Safety Data Sheet (SDS or MSDS), and look for these chemicals or their prefixes (bromine, chlorine, fluorine, or iodine). For example, the prefix "chlor-" in chloromethane or chlorine. If you have compounds with those names, is it a halogen? If yes, you can assume it is dangerous waste or you can test it.

WPCB code — Washington polychlorinated biphenyls

Polychlorinated biphenyls (PCBs) are very persistent — they last for decades in people, other animals, and the environment. In Washington, the WCPB code (WAC 173-303-9904) applies to undrained transformers, capacitors, and bushings containing PCB fluids with concentrations of 2 parts per million (ppm) or greater. It also includes certain wastes from salvaging, rebuilding, or discarding them. See the regulations (WAC 173-303-9904) for more information. Some of these wastes are excluded (see Step two).

WSC2 — solid corrosives

A solid or semi-solid waste can designate as corrosive if its pH is within the corrosive range. To test pH, use a solution of 50 percent deionized water and 50 percent of your waste material (you need water to be able to test pH). It is corrosive if the pH is:

  • Less than or equal to 2, or
  • Greater than or equal to 12.5.

Solid corrosives are not common. Cement or lime, for example, are solids that may test as corrosive.

Special wastes

Special wastes are a category of state-only excluded wastes with their own set of management requirements. They pose a relatively low hazard to human health and the environment. Special wastes are solid phase wastes that are state corrosive, level D toxic, or non-EHW persistent. You may be able to recycle special wastes or dispose of them in municipal landfills if you have the landfill authority’s approval. Learn more: