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 Code of Federal Regulations (Last Updated: November 8, 2024)
 Title 40 - Protection of Environment
 Chapter I - Environmental Protection Agency
 SubChapter I - Solid Wastes
 Part 266 - Standards for the Management of Specific Hazardous Wastes and Specific Types of Hazardous Waste Management Facilities

  Appendix IV to Part 266 - Reference Air Concentrations*  

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  • Appendix IV to Part 266 - Reference Air Concentrations*

    Constituent CAS No. RAC (ug/m3)
    Acetaldehyde 75-07-0 10
    Acetonitrile 75-05-8 10
    Acetophenone 98-86-2 100
    Acrolein 107-02-8 20
    Aldicarb 116-06-3 1
    Aluminum Phosphide 20859-73-8 0.3
    Allyl Alcohol 107-18-6 5
    Antimony 7440-36-0 0.3
    Barium 7440-39-3 50
    Barium Cyanide 542-62-1 50
    Bromomethane 74-83-9 0.8
    Calcium Cyanide 592-01-8 30
    Carbon Disulfide 75-15-0 200
    Chloral 75-87-6 2
    Chlorine (free) 0.4
    2-Chloro-1,3-butadiene 126-99-8 3
    Chromium III 16065-83-1 1000
    Copper Cyanide 544-92-3 5
    Cresols 1319-77-3 50
    Cumene 98-82-8 1
    Cyanide (free) 57-12-15 20
    Cyanogen 460-19-5 30
    Cyanogen Bromide 506-68-3 80
    Di-n-butyl Phthalate 84-74-2 100
    o-Dichlorobenzene 95-50-1 10
    p-Dichlorobenzene 106-46-7 10
    Dichlorodifluoromethane 75-71-8 200
    2,4-Dichlorophenol 120-83-2 3
    Diethyl Phthalate 84-66-2 800
    Dimethoate 60-51-5 0.8
    2,4-Dinitrophenol 51-28-5 2
    Dinoseb 88-85-7 0.9
    Diphenylamine 122-39-4 20
    Endosulfan 115-29-1 0.05
    Endrin 72-20-8 0.3
    Fluorine 7782-41-4 50
    Formic Acid 64-18-6 2000
    Glycidyaldehyde 765-34-4 0.3
    Hexachlorocyclopentadiene 77-47-4 5
    Hexachlorophene 70-30-4 0.3
    Hydrocyanic Acid 74-90-8 20
    Hydrogen Chloride 7647-01-1 7
    Hydrogen Sulfide 7783-06-4 3
    Isobutyl Alcohol 78-83-1 300
    Lead 7439-92-1 0.09
    Maleic Anhydride 108-31-6 100
    Mercury 7439-97-6 0.3
    Methacrylonitrile 126-98-7 0.1
    Methomyl 16752-77-5 20
    Methoxychlor 72-43-5 50
    Methyl Chlorocarbonate 79-22-1 1000
    Methyl Ethyl Ketone 78-93-3 80
    Methyl Parathion 298-00-0 0.3
    Nickel Cyanide 557-19-7 20
    Nitric Oxide 10102-43-9 100
    Nitrobenzene 98-95-3 0.8
    Pentachlorobenzene 608-93-5 0.8
    Pentachlorophenol 87-86-5 30
    Phenol 108-95-2 30
    M-Phenylenediamine 108-45-2 5
    Phenylmercuric Acetate 62-38-4 0.075
    Phosphine 7803-51-2 0.3
    Phthalic Anhydride 85-44-9 2000
    Potassium Cyanide 151-50-8 50
    Potassium Silver Cyanide 506-61-6 200
    Pyridine 110-86-1 1
    Selenious Acid 7783-60-8 3
    Selenourea 630-10-4 5
    Silver 7440-22-4 3
    Silver Cyanide 506-64-9 100
    Sodium Cyanide 143-33-9 30
    Strychnine 57-24-9 0.3
    1,2,4,5-Tetrachlorobenzene 95-94-3 0.3
    2,3,4,6-Tetrachlorophenol 58-90-2 30
    Tetraethyl Lead 78-00-2 0.0001
    Tetrahydrofuran 109-99-9 10
    Thallic Oxide 1314-32-5 0.3
    Thallium 7440-28-0 0.5
    Thallium (I) Acetate 563-68-8 0.5
    Thallium (I) Carbonate 6533-73-9 0.3
    Thallium (I) Chloride 7791-12-0 0.3
    Thallium (I) Nitrate 10102-45-1 0.5
    Thallium Selenite 12039-52-0 0.5
    Thallium (I) Sulfate 7446-18-6 0.075
    Thiram 137-26-8 5
    Toluene 108-88-3 300
    1,2,4-Trichlorobenzene 120-82-1 20
    Trichloromonofluoromethane 75-69-4 300
    2,4,5-Trichlorophenol 95-95-4 100
    Vanadium Pentoxide 1314-62-1 20
    Warfarin 81-81-2 0.3
    Xylenes 1330-20-7 80
    Zinc Cyanide 557-21-1 50
    Zinc Phosphide 1314-84-7 0.3

    *The RAC for other appendix VIII part 261 constituents not listed herein or in appendix V of this part is 0.1 ug/m.3

    [56 FR 7232, Feb. 21, 1991; 56 FR 32691, July 17, 1991, as amended at 71 FR 40277, July 14, 2006]