Section 84.126 - Canister bench tests; minimum requirements(a)(1) Bench tests, except for carbon monoxide tests, will be made on an apparatus that allows the test atmosphere at 50 ±5 percent relative humidity and room temperature (25 ±2.5 °C.) to enter the canister continuously at concentrations and rates of flow specified in Tables 5, 6, and 7 of this subpart.(2) Three canisters will be removed from containers and tested as received from the applicant.(3) Two canisters, other than those described in paragraph (a)(2) of this section, will be equilibrated at room temperature by passing 25 percent relative humidity air through them at 64 liters per minute for 6 hours.(4) Two canisters, other than those described in paragraphs (a) (2) and (3) of this section, will be equilibrated at room temperature by passing 85 percent relative humidity air through them at 64 liters per minute for 6 hours.(5) The equilibrated canisters will be resealed, kept in an upright position at room temperature, and tested within 18 hours.(b) Front-mounted and back-mounted gas mask canisters will be tested and shall meet the minimum requirements set forth in Table 5 of this subpart.(c)(1) Front-mounted, and back-mounted, and chin-style canisters designated as providing respiratory protection against gases, ammonia, organic vapors, carbon monoxide and particulate contaminants shall have a window or other indicator to warn the gas mask wearer when the canister will no longer satisfactorily remove carbon monoxide from the inhaled air.(2) Other types of front- and back-mounted canisters may also be equipped with a window or other indicator to warn of imminent leakage of other gases or vapors.(3) The window indicator canisters will be tested as regular canisters, but shall show a satisfactory indicator change or other warning before the allowable canister penetration has occurred.(d) Chin-style gas mask canisters shall meet the minimum requirements set forth in Table 6 of this subpart.(e) Escape gas mask canisters shall meet the minimum requirements set forth in Table 7 of this subpart.(f) Powered air-purifying respirators with a canister(s) and particulate filter(s) must meet the as-received minimum service-life requirements and half of the equilibrated minimum service-life requirements set forth in Tables 5, 6, and 7 of subpart I using the flows specified in subpart K, § 84.175(b) and equilibrated in accordance with paragraphs (a) through (e) of this section using the flows specified in subpart K, § 84.175(b) .60 FR 30355, June 8, 1995, as amended at 85 FR 20607, Apr. 14, 2020