IMC (International Mechanical Code) 2012
502.14 – Motor vehicle operation: In areas where motor vehicles operate, mechanical ventilation shall be provided in accordance with Section 403. Additionally, areas in which stationary motor vehicles are operated shall be provided with a source capture system that connects directly to the motor vehicle exhaust systems.
Definition of a source capture system:
Source Capture System – A mechanical exhaust system designed and constructed to capture air contaminants and to exhaust such contaminants to the outdoors. Such systems eliminate the release of contaminants into the space in which the source of contamination is located.
Federal Standards – To protect workers, the Department of Labor’s Occupational Safety and Health Administration has set permissible levels of the carbon monoxide gas in the workplace. Averaged over an eight hour workday, these may not exceed 50 ppm. Exposures higher than 100 parts per million are serious violations; 500 ppm and over is a state of imminent danger.
OSHA has adopted a proposal from the National Institute of Occupational Safety and Health to lower the average permissible exposure to 35 ppm, to forbid any exposure over 200 ppm, and to require other protective measures.