Indiana Indoor Air Published Levels - SVOCs and PAHs
IDEM Published Level Table 1 indoor air screening levels for SVOCs and PAHs in Indiana. 7 chemicals with residential and commercial/industrial values.
Overview
These are Indiana’s Published Level Table 1 indoor air screening levels for semi-volatile organic compounds (SVOCs) and polycyclic aromatic hydrocarbons (PAHs), from the IDEM Remediation Closure Guide (WASTE-0046-R2), effective March 28, 2025.
Only 7 chemicals. Most SVOCs and PAHs have very low vapor pressure and do not volatilize significantly from soil or groundwater to indoor air under typical conditions. As a result, Indiana publishes indoor air levels for only a small number of SVOCs - those that are sufficiently volatile to be relevant to vapor intrusion. Naphthalene is the most commonly encountered among them.
Risk basis: Indiana’s published levels use a 1E-05 cancer risk (1 in 100,000) and HQ of 1.0 - 10 times less conservative than EPA’s default 1E-06.
Vapor intrusion pathway: These values are used to evaluate the soil-to-indoor-air and groundwater-to-indoor-air pathways. Indiana does not publish separate soil-to-air attenuation factors; evaluators use the Soil Gas Screening Levels for direct subsurface comparison.
Qualifier key:
- C = Carcinogenic
- N = Noncarcinogenic
- D = Detection limit-based
Blank cells indicate no published level - not zero.
Indoor Air Published Levels - SVOCs and PAHs
| Chemical | CAS Number | Residential (µg/m3) | Q | Commercial/Industrial (µg/m3) | Q |
|---|---|---|---|---|---|
| Dichlorobenzene, 1,2- | 95-50-1 | 200 | N | 900 | N |
| Dichlorobenzene, 1,4- | 106-46-7 | 3 | C | 10 | C |
| Dimethylformamide | 68-12-2 | 30 | N | 100 | N |
| Dimethylhydrazine, 1,1- | 57-14-7 | 0.002 | N | 0.009 | N |
| Dimethylhydrazine, 1,2- | 540-73-8 | 0.0002 | C | 0.0008 | C |
| Nitrosodimethylamine, N- | 62-75-9 | 0.0007 | C | 0.009 | C |
| Tetrahydrofuran | 109-99-9 | 2,000 | N | 9,000 | N |
No results found.
Practical Notes
Naphthalene is the only PAH commonly evaluated in vapor intrusion assessments. It has a measurable vapor pressure and can volatilize from petroleum-contaminated soil and groundwater. It is frequently detected in indoor air at sites with weathered petroleum or coal tar impacts. Compare naphthalene indoor air concentrations or estimates to the residential and C/I values above.
Higher-molecular-weight PAHs (fluoranthene, pyrene, benzo(a)pyrene) have very low vapor pressures and are generally not relevant to the vapor intrusion pathway except under unusual circumstances such as direct contact with NAPL-phase coal tar or coal tar pitch. Their presence in this table reflects their theoretical volatility at very high soil concentrations, not typical site conditions.
For VOC vapor intrusion evaluation, see Indiana Indoor Air Published Levels - VOCs, which contains 137 chemicals and is the primary reference for vapor intrusion work at most Indiana sites.