StacksVerified U.S. regulatory reference

40 CFR Part 63, Table 2

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
For each fed-batch fermenter for which compliance is determined by monitoring brew ethanol concentration and calculating VOC concentration in the fermenter exhaust according to the procedures in § 63.2161, you must . . .Using . . .According to the following requirements . . .
Measure VOC as propaneMethod 25A,a or an alternative validated by EPA Method 301 b and approved by the AdministratorYou must measure the VOC concentration in the fermenter exhaust at any point prior to the dilution of the exhaust stream.

a EPA Test Method 25A is found in appendix A-7 of 40 CFR part 60.

b EPA Test Method 301 is found in appendix A of 40 CFR part 63.