VOC Content Calculator
Enter each volatile component of the formulation. Mark water and federally exempt compounds so they can be excluded from the “less water & exempt” figure.
VOC content =
300 g/L coating
(2.504 lb/gal)
VOC less water & exempt compounds =
375 g/L
(3.13 lb/gal)
This is a formulation-based ESTIMATEfrom the values you entered. The regulatory reference method (EPA Method 24) is a laboratory test and can diverge from formulation estimates. Compliance determinations require Method 24 or your permit's specified method.
40 CFR 51.100(s) (compound names verified against the primary text; the CAS numbers shown are not covered by that verification) (exempt-compound list) — as of 2026-07-12. eCFR. Federal exempt list only — California districts (CARB/ SCAQMD) differ; verify locally.
Reference only. Not legal or regulatory advice. Verify against the primary source before you act.
How it works
This calculator estimates VOC content from the volatile components you enter, using the standard mass-balance forms:
- VOC (g/L coating) = Mvoc / Vcoating
- VOC less water & exempt = Mvoc / (Vcoating − Vwater − Vexempt)
- Mvoc = total volatile mass − water mass − exempt-compound mass
Only the federal 40 CFR 51.100(s) exempt-compound list is used. California districts (CARB, SCAQMD) apply different exempt lists and are not covered — verify locally. This tool computes a number only; it never renders a compliance verdict against any named rule or limit.
40 CFR 51.100(s) (compound names verified against the primary text; the CAS numbers shown are not covered by that verification) — eCFR · as of 2026-07-12.
Worked example
A 1 L coating contains 300 g of a non-exempt solvent (density 0.86 g/mL) and 200 g of water (density 1.0 g/mL). Total volatile mass entered is 500 g; water mass is 200 g.
Mvoc = 500 − 200 = 300 g, so VOC = 300 / 1 = 300 g/L. Water volume is 200 / 1.0 / 1000 = 0.2 L, so VOC less water = 300 / (1 − 0.2) = 375 g/L .
Sources
Definition of volatile organic compounds and the exempt-compound list
U.S. Environmental Protection Agency, as of 2026-07-12
40 CFR 51.100(s) (compound names verified against the primary text; the CAS numbers shown are not covered by that verification)
Scope limitation: the tool carries 7 of the compounds named in 40 CFR 51.100(s)(1). The paragraph names more than the tool carries, and is amended by rulemaking, so a compound absent from the tool's list is not thereby non-exempt. Only the federal list applies here: California districts (CARB, SCAQMD) publish different exempt lists.
open the source
Related tools
- Percent Concentration Calculatornot yet live
- Unit Converternot yet live
Data vintage
- Data: EPA VOC-exempt compounds, U.S. Environmental Protection Agency current text as retrieved, retrieved 2026-07-12, 7 compounds.The tool carries 7 of the compounds named in (s)(1); the paragraph names more than the tool carries, and is amended by rulemaking. A compound absent from the tool's list is not thereby non-exempt. Only the federal list applies here: California districts (CARB, SCAQMD) publish different exempt lists.
last updated 2026-07-12