Note: This web page is a part of DTSC's Hazardous Waste Classification training course.

Acute and Extremely Hazardous Wastes

Acute and extremely hazardous wastes¹ are wastes that would cause death, disabling personal injury, or serious illness. These wastes are more hazardous than ordinary hazardous wastes.

Acute hazardous wastes include the “P-list” and the six dioxin-bearing wastes in the “F-List” in the federal system. Acute hazardous waste are identified as such based on the criterion²used to identify the acutely hazardous chemicals.

The criteria:

Separates highly toxic (acute hazardous) waste from other toxic wastes (U-listed wastes)
Establishes the management method for containers that held P-listed wastes

In California, we have identified extremely hazardous wastes with an asterisk in Appendix X. Identifying whether a hazardous waste is an extremely hazardous waste has a bearing on authorization under the tiered permitting system. A hazardous waste is extremely hazardous based on the following criteria:

Acute oral toxicity³ – LD₅₀ is less than or equal to 50 mg/kg.
Acute dermal toxicity⁴ – LD₅₀ is less than or equal to 43 mg/kg.
Acute inhalation toxicity⁵ – LC₅₀ is less than or equal to 100 ppm as a gas or vapor.
Carcinogenicity⁶ – Single or combined concentration equal to or exceeding 0.1 percent (1000 ppm) by weight.
Experience or testing⁷ – Like hazardous waste criteria, these wastes are shown through experience or testing to pose an extreme hazard.
Water reactive⁸ – When contacted by water, the waste reacts violently, generating extreme heat, burning, exploding or having some other rapid reaction.
Persistent and bioaccumulative⁹ toxic substances:

Substance	TTLC (Wet Weight in mg/kg)
Aldrin	140
Arsenic and/or arsenic compounds	50,000 (as As)
Beryllium and/or beryllium compounds	7,500 (as Be)
Cadmium and/or cadmium compounds	10,000 (as Cd)
Chlordane	250
2,4-Dichlorophenoxyacetic acid	10,000
Dieldren	800
Dioxin (2,3,7,8-TCDD)	1
Endrin	20
Heptachlor	470
Kepone	2,100
Lead compounds, organic	1,300 (dry weight basis; as Pb)
Lindane	400
Mercury and/or mercury compounds	2,000 (as Hg)
Mirex	2,100
Polychlorinated biphenyls (PCBs)	5,000
Selenium and/or selenium compounds	10,000 (as Se)
Thallium and/or thallium compounds	70,000 (as TI)
Toxaphene	500
2,4,5-Trichlorophenoxypropionic acid	1,000