Extremely Hazardous Waste

Some chemicals qualify as "Extremely Hazardous Waste" in the State of Washington. Many laboratory chemicals fall into this definition. If you have extremely hazardous chemicals in your workplace, please know and follow the more stringent hazardous waste accumulation limits and empty container disposal guidelines for them.

Use the MSDS of your chemical and the table below to determine whether your chemical falls into Toxic Category X, A or B. These limits apply only for concentrated or "pure" solutions of your chemical. If your chemical is diluted with water or mixed with other chemicals, you may take the dilution into account. To find out how, refer to Section 3 of the Laboratory Safety Manual (PDF). You may also send EH&S a Waste Evaluation Request and we will do the math for you.

(Note that the definition of Extremely Hazardous Waste is similar to that of Particularly Hazardous Substances.)

Toxic CategoryFish
LC50 (mg/L)
Oral (Rat)
LD50 (mg/kg)
Inhalation (Rat)
LD50 (mg/kg)
Dermal (Rabbit)
LC50 (mg/L)
X < 0.01 < 0.5 < 0.02 < 2
A 0.01 - < 0.1 0.5 - < 5 0.02 - < 0.2 2 - < 20
B 0.1 - < 1 5 - < 50 0.2 - < 2 20 - < 200
C 01 - < 10 50 - < 500 2 - < 20 200 - < 2000
D 10 - < 100 500 - < 5000 20 - < 200 2000 - < 20,000