Step five: Check Washington state-only criteria

In Washington state, businesses must check if their waste meets state-only dangerous waste criteria. This criteria is applied to wastes in addition to the federal toxic characteristic "F, P, U, or K" listed waste codes.

State-only criteria for:

  • Toxic wastes (coded WT01 or WT02) are determined based on the concentration of toxic components.
  • Persistent wastes (coded WP01, WP02, WPCB, or WP03) include polycyclic aromatic hydrocarbons (PAHs) halogenated organic compounds (HOCs), and some polychlorinated biphenyls (PCBs).
  • Solid corrosive wastes (coded WSC2) are solid or semi-solid wastes that have a pH that falls within the corrosive ranges listed below.

Is it a special waste?
Special wastes are a type of state-only dangerous waste that pose a relatively low hazard to human health and the environment. Generators can manage special wastes a couple different ways.

State-only toxic wastes

The concentration of a waste's toxic components determines if it meets state-only toxic criteria and how it should be coded:

Testing wastes for toxicity

You can test if a waste meets state-only toxic criteria by using the following methods.

How to verify test results against state-only toxic criteria

Once you know the test results for your waste:

  • Use the equation listed under dangerous waste criteria (WAC 173-303-100(5)(b)(ii)).
  • Based on that equation, determine if your waste meets the criteria noted in the Toxic Category Table (WAC 173-303-100(5)(b)(i)).

State-only persistent wastes

Persistent wastes have chemicals that are slow to break down, linger in the environment, and can accumulate in living tissue. Here are the types of persistent wastes to look out for.

State-only solid corrosives

Coded: WSC2

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% deionized water and 50% 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.