California Code of Regulations
Title 22 - Social Security
Division 4.5 - Environmental Health Standards for the Management of Hazardous Waste
Chapter 11 - Identification and Listing of Hazardous Waste
Article 3 - Characteristics of Hazardous Waste
Section 66261.24 - Characteristic of Toxicity

Universal Citation: 22 CA Code of Regs 66261.24

Current through Register 2024 Notice Reg. No. 38, September 20, 2024

(a) A waste exhibits the characteristic of toxicity if representative samples of the waste have any of the following properties:

(1) when using the Toxicity Characteristic Leaching Procedure (TCLP), test Method 1311 in "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods," EPA Publication SW-846, third edition and Updates (incorporated by reference in section 66260.11 of this division), the extracts from representative samples of the waste contain any of the contaminants listed in Table I of this section at a concentration equal to or greater than the respective value given in that table unless the waste is excluded from classification as a solid waste or hazardous waste or is exempted from regulation pursuant to 40 CFR section 261.4. Where the waste contains less than 0.5 percent filterable solids, the waste itself, after filtering using the methodology outlined in Method 1311, is considered to be the extract for the purposes of this section;
(A) a waste that exhibits the characteristic of toxicity pursuant to subsection (a)(1) of this section has the EPA Hazardous Waste Number specified in Table I of this section which corresponds to the toxic contaminant causing it to be hazardous;

(B) Table I - Maximum Concentration of Contaminants for the Toxicity Characteristic:

EPA Hazardous Waste Number ContaminantChemical Abstracts Service NumberRegulatory Level Mg/l
D004Arsenic7440-38-2 5.0
D005Barium7440-39-3100.0
D018Benzene71-43-2 0.5
D006Cadmium7440-43-9 1.0
D019Carbon tetrachloride56-23-5 0.5
D020Chlordane57-74-9 0.03
D021Chlorobenzene108-90-7100.0
D022Chloroform67-66-3 6.0
D007Chromium7440-47-3 5.0
D023o-Cresol95-48-7200.01
D024m-Cresol108-39-4200.01
D025p-Cresol106-44-5200.01
D026Cresol 200.01
D0162,4-D94-75-7 10.0
D0271,4-Dichlorobenzene106-46-7 7.5
D0281,2-Dichloroethane107-06-2 0.5
D0291,1-Dichloroethylene75-35-4 0.7
D0302,4-Dinitrotoluene121-14-2 0.13
D012Endrin72-20-8 0.02
D031Heptachlor (and its epoxide)76-44-8 0.008
D032Hexachlorobenzene118-74-1 0.13
D033Hexachlorobutadiene87-68-3 0.5
D034Hexachloroethane67-72-1 3.0
D008Lead7439-92-1 5.0
D013Lindane58-89-9 0.4
D009Mercury7439-97-6 0.2
D014Methoxychlor72-43-5 10.0
D035Methyl ethyl ketone78-93-3200.0
D036Nitrobenzene98-95-3 2.0
D037Pentachlorophenol87-86-5100.0
D038Pyridine110-86-1 5.02
D010Selenium7782-49-2 1.0
D011Silver7440-22-4 5.0
D039Tetrachloroethylene127-18-4 0.7
D015Toxaphene8001-35-2 0.5
D040Trichloroethylene79-01-6 0.5
D0412,4,5-Trichlorophenol95-95-4400.0
D0422,4,6-Trichlorophenol88-06-2 2.0
D0172,4,5-TP (Silvex)93-72-1 1.0
D043Vinyl chloride75-01-4 0.2

1 If o-, m- and p-Cresol concentrations cannot be differentiated, the total cresol (D026) concentration is used. The regulatory level of total cresol is 200 mg/l.

2 Quantitation limit is greater than the calculated regulatory level. The quantitation limit therefore becomes the regulatory level.

(2) it contains a substance listed in subsections (a)(2)(A) or (a)(2)(B) of this section at a concentration in milligrams per liter of waste extract, as determined using the Waste Extraction Test (WET) described in Appendix II of this chapter, which equals or exceeds its listed soluble threshold limit concentration or at a concentration in milligrams per kilogram in the waste which equals or exceeds its listed total threshold limit concentration;
(A) Table II - List of Inorganic Persistent and Bioaccumulative Toxic Substances and Their Soluble Threshold Limit Concentration:

(STLC) and Total Threshold Limit Concentration (TTLC) Values.

STLC

TTLC

Substancea, b

mg/l

Wet-Weight mg/kg
Antimony and/or antimony compounds15500
Arsenic and/or arsenic compounds5.0500
Asbestos 1.0
(as percent)
Barium and/or barium compounds (excluding barite)10010,000c
Beryllium and/or beryllium compounds0.7575
Cadmium and/or cadmium compounds1.0100
Chromium (VI) compounds5500
Chromium and/or chromium (III) compounds5d2,500
Cobalt and/or cobalt compounds808,000
Copper and/or copper compounds252,500
Fluoride salts18018,000
Lead and/or lead compounds5.01,000
Mercury and/or mercury compounds0.220
Molybdenum and/or molybdenum compounds3503,500e
Nickel and/or nickel compounds202,000
Selenium and/or selenium compounds1.0100
Silver and/or silver compounds5500
Thallium and/or thallium compounds7.0700
Vanadium and/or vanadium compounds242,400
Zinc and/or zinc compounds2505,000

a STLC and TTLC values are calculated on the concentrations of the elements, not the compounds.

b In the case of asbestos and elemental metals, the specified concentration limits apply only if the substances are in a friable, powdered or finely divided state. Asbestos includes chrysotile, amosite, crocidolite, tremolite, anthophyllite, and actinolite.

c Excluding barium sulfate.

d If the soluble chromium, as determined by the TCLP set forth in Appendix I of chapter 18 of this division, is less than 5 mg/l, and the soluble chromium, as determined by the procedures set forth in Appendix II of chapter 11, equals or exceeds 560 mg/l and the waste is not otherwise identified as a RCRA hazardous waste pursuant to section 66261.100, then the waste is a non-RCRA hazardous waste.

e Excluding molybdenum disulfide.

(B) Table III - List of Organic Persistent and Bioaccumulative Toxic Substances and Their Soluble Threshold Limit Concentration (STLC) and Total Threshold Limit Concentration (TTLC) Values:

STLCTTLC
Substancemg/lWet-Weight mg/kg
Aldrin0.141.4
Chlordane0.252.5
DDT, DDE, DDD0.11.0
2,4-Dichlorophenoxyacetic acid10100
Dieldrin0.88.0
Dioxin (2,3,7,8-TCDD)0.0010.01
Endrin0.020.2
Heptachlor0.474.7
Kepone2.121
Lead compounds, organic--13
Lindane0.44.0
Methoxychlor10100
Mirex2.121
Pentachlorophenol1.717
Polychlorinated biphenyls (PCBs)5.050
Toxaphene0.55
Trichloroethylene2042,040
2,4,5-Trichlorophenoxypropionic acid1.010

(3) it has an acute oral LD50 less than 2,500 milligrams per kilogram;

(4) it has an acute dermal LD50 less than 4,300 milligrams per kilogram;

(5) it has an acute inhalation LC50 less than 10,000 parts per million as a gas or vapor;

(6) it has an acute aquatic 96-hour LC50 less than 500 milligrams per liter when measured in soft water (total hardness 40 to 48 milligrams per liter of calcium carbonate) with fathead minnows (Pimephales promelas), rainbow trout (Salmo gairdneri) or golden shiners (Notemigonus crysoleucas) according to procedures described in Part 800 of the "Standard Methods for the Examination of Water and Wastewater (16th Edition)," American Public Health Association, 1985 and "Static Acute Bioassay Procedures for Hazardous Waste Samples," California Department of Fish and Game, Water Pollution Control Laboratory, revised November 1988 (incorporated by reference, see section 66260.11), or by other test methods or test fish approved by the Department, using test samples prepared or meeting the conditions for testing as prescribed in subdivisions (c) and (d) of Appendix II of this chapter, and solubilized, suspended, dispersed or emulsified by the cited procedures or by other methods approved by the Department;

(7) it contains any of the following substances at a single or combined concentration equal to or exceeding 0.001 percent by weight:
(A) 2-Acetylaminofluorene (2-AAF);

(B) Acrylonitrile;

(C) 4-Aminodiphenyl;

(D) Benzidine and its salts;

(E) bis (Chloromethyl) ether (BCME);

(F) Methyl chloromethyl ether;

(G) 1,2-Dibromo-3-chloropropane (DBCP);

(H) 3,3'-Dichlorobenzidine and its salts (DCB);

(I) 4-Dimethylaminoazobenzene (DAB);

(J) Ethyleneimine (EL);

(K) alpha-Naphthylamine (1-NA);

(L) beta-Naphthylamine (2-NA);

(M) 4-Nitrobiphenyl (4-NBP);

(N) N-Nitrosodimethylamine (DMN);

(O) beta-Propiolactone (BPL);

(P) Vinyl chloride (VCM);

(8) it has been shown through experience or testing to pose a hazard to human health or environment because of its carcinogenicity, acute toxicity, chronic toxicity, bioaccumulative properties or persistence in the environment.

(b) A waste containing one or more materials which exhibit the characteristic of toxicity because the materials have the property specified in subsection (a)(5) of this section may be classified as nonhazardous pursuant to section 66260.200 if the waste does not exhibit any other characteristic of this article and is not listed in article 4 of this chapter and its head space vapor contains no such toxic materials in concentrations exceeding their respective acute inhalation LC50 or their LCLO. The head space vapor of a waste shall be prepared, and two milliliters of it shall be sampled using a five milliliter gas-tight syringe, according to Method 5020 in "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods," SW-846, 2nd edition, U.S. Environmental Protection Agency, 1982 (incorporated by reference, see section 66260.11). The quantity in milligrams of each material, which exhibits the characteristic of toxicity because it has the property specified in subsection (a)(5) of this section, in the sampling syringe shall be determined by comparison to liquid standard solutions according to the appropriate gas chromatographic procedures in Method 8010, 8015, 8020, 8030 or 8240 in "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods," SW-846, 3rd edition, U.S. Environmental Protection Agency, 1986 (incorporated by reference, see section 66260.11). The concentration of each material in the head space vapor shall be calculated using the following equation:

Click here to view image

where C (in parts per million) is the concentration of material A in head space vapor, Q (in milligrams) is the quantity of material A in sampling syringe and MW (in milligrams per millimole) is the molecular weight of material A. Where an acute inhalation LC50 is not available, an LC50 measured for another time (t) may be converted to an eight-hour value with the following equation:

Eight-hour LC50 = (t/8) x (t-hour LC50).

(c) A waste containing one or more materials which exhibit the characteristic of toxicity because the materials have either of the properties specified in subsection (a)(3) or (a)(4) of this section may be classified as nonhazardous pursuant to section 66260.200 if the waste does not exhibit any other characteristic of this article and is not listed in article 4 of this chapter and the calculated oral LD50 of the waste mixture is greater than 2,500 milligrams per kilogram and the calculated dermal LD50 is greater than 4,300 milligrams per kilogram by the following equation:

Click here to view image

where % Ax is the weight percent of each component in the waste mixture and TAx is the acute oral or dermal LD50 or the acute oral LDLO of each component.

1. New section filed 5-24-91; effective 7-1-91 (Register 91, No. 22).
2. Amendment of table II filed 1-31-94; operative 1-31-94 (Register 94, No. 5).
3. Editorial correction of equation (Register 95, No. 36).
4. Amendment of subsection (a)(1) and NOTE filed 10-13-98; operative 11-12-98 (Register 98, No. 42).
5. Change without regulatory effect amending subsections (a)(3) and (c) filed 6-3-2004 pursuant to section 100, title 1, California Code of Regulations (Register 2004, No. 23).
6. Editorial correction redesignating subsection (a)(7)(0) as (a)(7)(O) (Register 2015, No. 33).

Note: Authority cited: Sections 25141, 25159, 58004 and 58012, Health and Safety Code. Reference: Sections 25117, 25120.2, 25141, 25159 and 25159.5, Health and Safety Code and 40 CFR Section 261.24.

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