40 CFR Part 63, Table 4 — Default Organic HAP Mass Fraction for Petroleum Solvent Groups 1
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
You May Use the Mass Fraction Values in the Following Fable for Solvent Blends for Which You Do Not Have Test Data or Manufacturer's Formulation Data:
| Solvent type | Average organic HAP mass fraction | Typical organic percent HAP, by mass |
|---|---|---|
| Aliphatic 2 | 0.03 | 1% Xylene, 1% Toluene, and 1% Ethylbenzene. |
| Aromatic 3 | 0.06 | 4% Xylene, 1% Toluene, and 1% Ethylbenzene. |
1 Use this table only if the solvent blend does not match any of the solvent blends in Table 3 to this subpart and you only know whether the blend is aliphatic or aromatic.
2 E.g., Mineral Spirits 135, Mineral Spirits 150 EC, Naphtha, Mixed Hydrocarbon, Aliphatic Hydrocarbon, Aliphatic Naphtha, Naphthol Spirits, Petroleum Spirits, Petroleum Oil, Petroleum Naphtha, Solvent Naphtha, Solvent Blend.
3 E.g., Medium-flash Naphtha, High-flash Naphtha, Aromatic Naphtha, Light Aromatic Naphtha, Light Aromatic Hydrocarbons, Aromatic Hydrocarbons, Light Aromatic Solvent.