(a) The stunning area shall be adequately ventilated and the employee exposure monitored in accordance with Title 8, section 5155 of the California Code of Regulations. Carbon dioxide and argon gas are heavier than air, and therefore may accumulate in the stunning area.

(b) A record of the calibration and maintenance of all measuring instruments shall be available for inspection by the Department inspector or PMI. All maintenance shall be performed by qualified personnel.

(c) The carbon dioxide, nitrogen, and/or argon gas shall be administered in a chamber or, in the case of ratites, via a properly fitted mask or hood, which accomplishes effective exposure of poultry. Chamber operations shall be in accordance with manufacturer's specifications and instructions.

(d) Chambers and all auxiliary equipment shall be designed to properly accommodate the species of poultry being stunned or killed.

(e) A uniform carbon dioxide, nitrogen, and/or argon gas concentration and distribution shall be maintained within the chamber to produce effective stunning. The system shall provide for mechanical agitation so that a concentration of carbon dioxide, nitrogen, and/or argon gas is sufficient to accomplish effective stunning and is uniform throughout the chamber. The poultry slaughter establishment shall sample the concentration of gas for analysis from a representative place or places within the chamber on a continuing basis.

(f) Neither carbon dioxide, nitrogen, and/or argon gas nor atmospheric air used in the chambers shall contain irritating gases.