Regulations last checked for updates: Jan 18, 2025

Title 40 - Protection of Environment last revised: Dec 30, 2025
Appendix - Table 3 to Subpart A of Part 65—Detection Sensitivity Levels (grams per hour)
Monitoring Frequency per Subpart a Detection
Sensitivity
Level
Bi-Monthly60
Semi-Quarterly85
Monthly100

a When this alternative work practice is used to identify leaking equipment, the owner or operator must choose one of the monitoring frequencies listed in this table, in lieu of the monitoring frequency specified in the applicable subpart. Bi-monthly means every other month. Semi-quarterly means twice per quarter. Monthly means once per month.

[73 FR 78219, Dec. 22, 2008]
authority: 42 U.S.C. 7401
source: 65 FR 78285, Dec. 14, 2000, unless otherwise noted.