§75.322. Harmful quantities of noxious gases. — Inbound Citations

(b) Notwithstanding the provisions of § 75.322, for the purpose of preventing explosions from gases other than methane, the following gases shall not be permitted to accumulate in excess of the concentrations listed below:

(1) 2.5 percent

(2) .80 percent

(3) .80 percent

(4) .40 percent

(5) .40 percent

(6) .30 percent