air

Indiana Soil Gas Screening Levels

IDEM soil gas screening levels for vapor intrusion. Subslab, deep exterior, and shallow exterior values for 3 land uses. 154 chemicals.

Verified March 31, 2026 Source: IDEM Remediation Closure Guide (WASTE-0046-R2)

Overview

Indiana’s soil gas screening levels allow direct comparison of soil gas measurements to regulatory thresholds without requiring an attenuation factor calculation. They are derived by applying IDEM’s published attenuation factors to the indoor air published levels, working backwards to the subsurface concentration that would produce an indoor air concentration at or below the indoor air published level. Published in the IDEM Remediation Closure Guide (WASTE-0046-R2), effective March 28, 2025.

Two sampling categories, six columns:

IDEM publishes soil gas levels for two depth categories and three land use scenarios:

  • Subslab and deep exterior (>5 feet depth): Soil gas collected from beneath a slab or from exterior probes deeper than 5 feet below grade. These locations are closer to building entry points and use less conservative (higher) attenuation factors.
  • Shallow exterior (within 5 feet of ground surface): Soil gas collected from shallow exterior probes. These locations are farther from building interiors and use more conservative (lower) attenuation factors that account for additional dilution.

Three land use scenarios:

  • Residential
  • Commercial
  • Large commercial (buildings >10,000 ft2, which have greater dilution volume)

Risk basis: Derived from Indiana’s 1E-05 cancer risk, HQ of 1.0 indoor air published levels.

Qualifier key:

  • C = Carcinogenic
  • N = Noncarcinogenic
  • S = Soil saturation cap
  • D = Detection limit-based

Blank cells indicate no published soil gas level for that chemical in that scenario - not zero.

Unique to Indiana: Ohio’s CIDARS system does not publish soil gas screening levels. This is an Indiana-specific feature that simplifies vapor intrusion assessment by enabling direct soil gas measurement comparisons without attenuation factor calculations.

Soil Gas Screening Levels

Column headers:

  • Sub/Deep Res = Subslab or deep exterior, residential (µg/m3)
  • Sub/Deep Com = Subslab or deep exterior, commercial (µg/m3)
  • Sub/Deep LgCom = Subslab or deep exterior, large commercial (µg/m3)
  • Shallow Res = Shallow exterior, residential (µg/m3)
  • Shallow Com = Shallow exterior, commercial (µg/m3)
  • Shallow LgCom = Shallow exterior, large commercial (µg/m3)
Showing 154 of 154 chemicals
Chemical CAS Number Sub/Deep Res (µg/m3) Q Sub/Deep Com (µg/m3) Q Sub/Deep LgCom (µg/m3) Q Shallow Res (µg/m3) Q Shallow Com (µg/m3) Q Shallow LgCom (µg/m3) Q
Acetaldehyde75-07-0300N1,000N10,000N90N400N4,000N
Acetonitrile75-05-82,000N9,000N90,000N600N3,000N30,000N
Acrolein107-02-80.7N3N30N0.2N0.9N9N
Acrylic Acid79-10-77N30N300N2N9N90N
Acrylonitrile107-13-110C60C600C4C20C200C
Allyl Alcohol107-18-63N10N100N1N4N40N
Allyl Chloride107-05-130N100N1,000N10N40N400N
Ammonia7664-41-720,000N70,000N700,000N5,000N20,000N200,000N
Amyl Alcohol, tert-75-85-4100N400N4,000N30N100N1,000N
Benzene71-43-2100C500C5,000C40C200C2,000C
Benzene, Trimethyl25551-13-7100N600N6,000N40N200N2,000N
Benzyl Chloride100-44-720C80C800C6C30C300C
Bis(2-chloroethyl)ether111-44-43C10C100C0.9C4C40C
Bis(chloromethyl)ether542-88-10.02C0.07C0.7C0.005C0.02C0.2C
Boron Trichloride10294-34-5700N3,000N30,000N200N900N9,000N
Boron Trifluoride7637-07-2500N2,000N20,000N100N600N6,000N
Bromo-2-chloroethane, 1-107-04-02N9N90N0.6N3N30N
Bromobenzene108-86-12,000N9,000N90,000N600N3,000N30,000N
Bromochloromethane74-97-51,000N6,000N60,000N400N2,000N20,000N
Bromodichloromethane75-27-430C100C1,000C8C30C300C
Bromoform75-25-2900C4,000C40,000C300C1,000C10,000C
Bromomethane74-83-9200N700N7,000N50N200N2,000N
Bromopropane, 1-106-94-5300C1,000C10,000C80C300C3,000C
Butadiene, 1,3-106-99-030C100C1,000C9C40C400C
Butyl alcohol, sec-78-92-21,000,000N4,000,000N40,000,000N300,000N1,000,000N10,000,000N
Butyl Alcohol, t-75-65-0200,000N700,000N7,000,000N50,000N200,000N2,000,000N
Carbon Disulfide75-15-020,000N100,000N1,000,000N7,000N30,000N300,000N
Carbon Tetrachloride56-23-5200C700C7,000C50C200C2,000C
Carbonyl Sulfide463-58-13,000N10,000N100,000N1,000N4,000N40,000N
Chlorine7782-50-55N20N200N2N6N60N
Chlorine Dioxide10049-04-47N30N300N2N9N90N
Chloro-1,1-difluoroethane, 1-75-68-32,000,000N7,000,000N70,000,000N500,000N2,000,000N20,000,000N
Chloro-1,3-butadiene, 2- (Chloroprene)126-99-81C10C100C0.3C4C40C
Chlorobenzene108-90-72,000N7,000N70,000N500N2,000N20,000N
Chlorobenzotrifluoride, 4-98-56-6100C500C5,000C30C100C1,000C
Chlorodifluoromethane75-45-62,000,000N7,000,000N70,000,000N500,000N2,000,000N20,000,000N
Chloroform67-66-340C200C2,000C10C50C500C
Chloromethane74-87-33,000N10,000N100,000N900N4,000N40,000N
Chloromethyl Methyl Ether107-30-21C6C60C0.4C2C20C
Chloropicrin76-06-210N60N600N4N20N200N
Cumene98-82-810,000N60,000N600,000N4,000N20,000N200,000N
Cyanide (CN-)57-12-530N100N1,000N8N40N400N
Cyclohexane110-82-7200,000N900,000N9,000,000N60,000N300,000N3,000,000N
Cyclohexanone108-94-120,000N100,000N1,000,000N7,000N30,000N300,000N
Cyclohexene110-83-830,000N100,000N1,000,000N10,000N40,000N400,000N
Dibromoethane, 1,2-106-93-42C7C70C0.5C2C20C
Dibromomethane (Methylene Bromide)74-95-3100N600N6,000N40N200N2,000N
Dichloro-2-butene, 1,4-764-41-00.2C1C10C0.07C0.3C3C
Dichloro-2-butene, cis-1,4-1476-11-50.2C1C10C0.07C0.3C3C
Dichloro-2-butene, trans-1,4-110-57-60.2C1C10C0.07C0.3C3C
Dichlorobenzene, 1,2-95-50-17,000N30,000N300,000N2,000N9,000N90,000N
Dichlorobenzene, 1,4-106-46-790C400C4,000C30C100C1,000C
Dichlorodifluoromethane75-71-83,000N10,000N100,000N1,000N4,000N40,000N
Dichloroethane, 1,1-75-34-3600C3,000C30,000C200C800C8,000C
Dichloroethane, 1,2-107-06-240C200C2,000C10C50C500C
Dichloroethylene, 1,1-75-35-4100N600N6,000N40N200N2,000N
Dichloroethylene, cis-1,2-156-59-21,000N6,000N60,000N400N2,000N20,000N
Dichloroethylene, trans-1,2-156-60-51,000N6,000N60,000N400N2,000N20,000N
Dichloropropane, 1,2-78-87-5100N600N6,000N40N200N2,000N
Dichloropropene, 1,3-542-75-6200C1,000C10,000C70C300C3,000C
Dicyclopentadiene77-73-610N40N400N3N10N100N
Difluoroethane, 1,1-75-37-61,000,000N6,000,000N60,000,000N400,000N2,000,000N20,000,000N
Difluoropropane, 2,2-420-45-11,000,000N4,000,000N40,000,000N300,000N1,000,000N10,000,000N
Diisopropyl Ether108-20-320,000N100,000N1,000,000N7,000N30,000N300,000N
Dimethyl Sulfide75-18-37N30N300N2N9N90N
Dimethylformamide68-12-21,000N4,000N40,000N300N1,000N10,000N
Dimethylhydrazine, 1,1-57-14-70.07N0.3N3N0.02N0.09N0.9N
Dimethylhydrazine, 1,2-540-73-80.006C0.03C0.3C0.002C0.008C0.08C
Dimethylvinylchloride513-37-170C300C3,000C20C90C900C
Dioxane, 1,4-123-91-1200C800C8,000C60C300C3,000C
Epichlorohydrin106-89-830N100N1,000N10N40N400N
Epoxybutane, 1,2-106-88-7700N3,000N30,000N200N900N9,000N
Ethoxyethanol Acetate, 2-111-15-92,000N9,000N90,000N600N3,000N30,000N
Ethoxyethanol, 2-110-80-51,000N6,000N60,000N400N2,000N20,000N
Ethyl Acetate141-78-62,000N10,000N100,000N700N3,000N30,000N
Ethyl Acrylate140-88-5300N1,000N10,000N80N400N4,000N
Ethyl Chloride (Chloroethane)75-00-3100,000N600,000N6,000,000N40,000N200,000N2,000,000N
Ethyl Methacrylate97-63-210,000N40,000N400,000N3,000N10,000N100,000N
Ethyl Tertiary Butyl Ether (ETBE)637-92-310,000C50,000C500,000C4,000C20,000C200,000C
Ethylbenzene100-41-4400C2,000C20,000C100C500C5,000C
Ethylene Oxide75-21-80.1C1C10C0.03C0.4C4C
Ethyleneimine151-56-40.05C0.2C2C0.02C0.07C0.7C
Formaldehyde50-00-050C600C6,000C10C200C2,000C
Formic Acid64-18-610N40N400N3N10N100N
Furfural98-01-12,000N7,000N70,000N500N2,000N20,000N
Glycidaldehyde765-34-430N100N1,000N10N40N400N
Heptanal, n-111-71-7100N400N4,000N30N100N1,000N
Heptane, N-142-82-510,000N60,000N600,000N4,000N20,000N200,000N
Hexane, CommercialE52419975,000C20,000C200,000C1,000C6,000C60,000C
Hexane, N-110-54-320,000N100,000N1,000,000N7,000N30,000N300,000N
Hexanone, 2-591-78-61,000N4,000N40,000N300N1,000N10,000N
Hydrazine302-01-20.2C0.8C8C0.06C0.3C3C
Hydrogen Chloride7647-01-0700N3,000N30,000N200N900N9,000N
Hydrogen Cyanide74-90-830N100N1,000N8N40N400N
Hydrogen Fluoride7664-39-3500N2,000N20,000N200N600N6,000N
Hydrogen Sulfide7783-06-470N300N3,000N20N90N900N
Isobutyl Alcohol78-83-110,000N60,000N600,000N4,000N20,000N200,000N
Isopropanol67-63-07,000N30,000N300,000N2,000N9,000N90,000N
Isopropyltoluene, p-99-87-61,000N6,000N60,000N400N2,000N20,000N
Jet propulsion fuel 7 (JP-7)E173766510,000N40,000N400,000N3,000N10,000N100,000N
Methacrylonitrile126-98-71,000N4,000N40,000N300N1,000N10,000N
Methanol67-56-1700,000N3,000,000N30,000,000N200,000N900,000N9,000,000N
Methoxyethanol Acetate, 2-110-49-630N100N1,000N10N40N400N
Methoxyethanol, 2-109-86-4200N1,000N10,000N70N300N3,000N
Methyl Acrylate96-33-3700N3,000N30,000N200N900N9,000N
Methyl Ethyl Ketone (2-Butanone)78-93-3200,000N700,000N7,000,000N50,000N200,000N2,000,000N
Methyl Hydrazine60-34-40.7N3N30N0.2N0.9N9N
Methyl Isobutyl Ketone (4-methyl-2-pentanone)108-10-1100,000N400,000N4,000,000N30,000N100,000N1,000,000N
Methyl Isocyanate624-83-930N100N1,000N10N40N400N
Methyl Methacrylate80-62-620,000N100,000N1,000,000N7,000N30,000N300,000N
Methyl Styrene (Mixed Isomers)25013-15-41,000N6,000N60,000N400N2,000N20,000N
Methyl tert-Butyl Ether (MTBE)1634-04-44,000C20,000C200,000C1,000C5,000C50,000C
Methyl-2-Pentanol, 4-108-11-2100,000N400,000N4,000,000N30,000N100,000N1,000,000N
Methylcyclohexane108-87-23,000N10,000N100,000N1,000N4,000N40,000N
Methylene Chloride75-09-220,000N90,000N900,000N6,000N30,000N300,000N
Nickel Carbonyl13463-39-30.5N2N20N0.2N0.6N6N
Nitromethane75-52-5100C500C5,000C30C100C1,000C
Nitropropane, 2-79-46-92C7C70C0.5C2C20C
Nitrosodimethylamine, N-62-75-90.02C0.3C3C0.007C0.09C0.9C
Nitrosomethylethylamine, N-10595-95-60.2C0.6C6C0.05C0.2C2C
Nonane, n-111-84-2700N3,000N30,000N200N900N9,000N
Pentane, n-109-66-030,000N100,000N1,000,000N10,000N40,000N400,000N
Phosgene75-44-510N40N400N3N10N100N
Phosphine7803-51-210N40N400N3N10N100N
Propionaldehyde123-38-6300N1,000N10,000N80N400N4,000N
Propyl benzene103-65-130,000N100,000N1,000,000N10,000N40,000N400,000N
Propylene115-07-1100,000N400,000N4,000,000N30,000N100,000N1,000,000N
Propylene Glycol Monomethyl Ether107-98-270,000N300,000N3,000,000N20,000N90,000N900,000N
Propylene Oxide75-56-9300C1,000C10,000C80C300C3,000C
Styrene100-42-530,000N100,000N1,000,000N10,000N40,000N400,000N
Sulfur Trioxide7446-11-930N100N1,000N10N40N400N
Tert-Butyl Acetate540-88-5700C3,000C30,000C200C900C9,000C
Tetrachloroethane, 1,1,1,2-630-20-6100C600C6,000C40C200C2,000C
Tetrachloroethane, 1,1,2,2-79-34-520C70C700C5C20C200C
Tetrachloroethylene127-18-41,000N6,000N60,000N400N2,000N20,000N
Tetrafluoroethane, 1,1,1,2-811-97-23,000,000N10,000,000N100,000,000N800,000N4,000,000N40,000,000N
Tetrahydrofuran109-99-970,000N300,000N3,000,000N20,000N90,000N900,000N
Titanium Tetrachloride7550-45-03N10N100N1N4N40N
Toluene108-88-3200,000N700,000N7,000,000N50,000N200,000N2,000,000N
Trichloro-1,2,2-trifluoroethane, 1,1,2-76-13-1200,000N700,000N7,000,000N50,000N200,000N2,000,000N
Trichloroethane, 1,1,1-71-55-6200,000N700,000N7,000,000N50,000N200,000N2,000,000N
Trichloroethane, 1,1,2-79-00-57N30N300N2N9N90N
Trichloroethylene79-01-670N300N3,000N20N90N900N
Trichloropropane, 1,2,3-96-18-410N40N400N3N10N100N
Trichloropropene, 1,2,3-96-19-510N40N400N3N10N100N
Triethylamine121-44-8200N1,000N10,000N70N300N3,000N
Trifluoroethane, 1,1,1-420-46-2700,000N3,000,000N30,000,000N200,000N900,000N9,000,000N
Trimethylbenzene, 1,2,3-526-73-82,000N9,000N90,000N600N3,000N30,000N
Trimethylbenzene, 1,2,4-95-63-62,000N9,000N90,000N600N3,000N30,000N
Trimethylbenzene, 1,3,5-108-67-82,000N9,000N90,000N600N3,000N30,000N
Vinyl Acetate108-05-47,000N30,000N300,000N2,000N9,000N90,000N
Vinyl Bromide593-60-260C300C3,000C20C80C800C
Vinyl Chloride75-01-460C900C9,000C20C300C3,000C
Xylenes1330-20-73,000N10,000N100,000N1,000N4,000N40,000N

Practical Notes

Choosing the right column: Match the column to your sampling location and the building type at or nearest to the sample location:

  • Sub-slab probes or exterior probes deeper than 5 feet: use the Sub/Deep columns
  • Exterior probes within 5 feet of grade: use the Shallow columns
  • Residential buildings, apartments, schools: use the Res columns
  • Commercial buildings under 10,000 ft2: use the Com columns
  • Large commercial or industrial buildings over 10,000 ft2: use the LgCom columns

Soil gas sampling methods: IDEM guidance references EPA’s Vapor Intrusion Technical Guide and ITRC guidance documents for soil gas sampling methodology. Proper probe installation, purging, leak testing, and sample collection are critical to obtaining representative results. A soil gas sample with a leak will underestimate concentrations and produce a false negative.

Indoor air vs. soil gas: When both indoor air and soil gas data are available, compare each to the appropriate published level. An exceedance of the soil gas level alone does not mean indoor air is impacted - building characteristics, HVAC systems, and seasonal variation affect actual indoor air concentrations. Conversely, indoor air may be impacted even if soil gas is below the screening level if other sources of VOC vapors exist in or near the building.

Relationship to indoor air levels: The soil gas screening levels on this page are mathematically derived from the Indiana Indoor Air Published Levels - VOCs. If soil gas results are below the screening level for the applicable scenario, indoor air concentrations are expected to be below the indoor air published level assuming IDEM’s standard attenuation factors. Site-specific conditions may warrant a more detailed evaluation.