Washington State Department of Ecology
Washington designates "dangerous waste" beyond the federal RCRA baseline. WAC 173-303-104 defines the state-specific waste numbers: toxicity (WT), persistence (WP), state-only solid corrosives (WSC2) and source-listed PCB wastes (WPCB).
7 state-only codes · EHW and DW designationsA waste stream in Washington can be a federal hazardous waste (carrying RCRA codes), a state-only dangerous waste (DW), or an extremely hazardous waste (EHW — the stricter state tier triggered by WT01, WP01 or WP03). State-only designation matters commercially: streams that are "nonhazardous" federally may still need permitted handling in Washington.
| Code | Description | Designation |
|---|---|---|
| WT01 | Toxic dangerous waste designated as extremely hazardous waste (equivalent concentration >= 1%) | Extremely Hazardous |
| WT02 | Toxic dangerous waste designated as dangerous waste (equivalent concentration below 1% but above 0.001%) | Dangerous Waste |
| WP01 | Halogenated organic compound persistent dangerous waste, extremely hazardous waste category (HOC >= 1%) | Extremely Hazardous |
| WP02 | Halogenated organic compound persistent dangerous waste, dangerous waste category (HOC 0.01% to 1%) | Dangerous Waste |
| WP03 | Polycyclic aromatic hydrocarbon persistent dangerous waste, extremely hazardous waste category (PAH >= 1%) | Extremely Hazardous |
| WSC2 | State-only solid corrosive waste | Dangerous Waste |
| WPCB | State source-listed PCB wastes per WAC 173-303-9904 | Dangerous Waste |
Book designation or bioassay: wastes designate by equivalent concentration of toxic constituents. At or above 1% equivalent concentration the waste is extremely hazardous (WT01); between 0.001% and 1% it is dangerous waste (WT02). WAC 173-303-100(5).
Halogenated organic compounds (HOC) and polycyclic aromatic hydrocarbons (PAH) that resist degradation. HOC at 1% or more designates EHW (WP01), 0.01% to 1% designates DW (WP02); PAH at 1% or more designates EHW (WP03). WAC 173-303-100(6).
Washington regulates solid corrosive wastes that the federal D002 characteristic (liquids only) does not capture.
PCB wastes listed by Washington state sources under WAC 173-303-9904, beyond federal TSCA coverage.
SymbioFlows identifies verified off-takers for your specific waste stream and generates a compliance-grounded recovery analysis.
Request Recovery AnalysisReviewed by our regulatory specialist within 1 business day.