Vehicle Exhaust Guidelines:
IMC (International Mechanical Code)
BOCA (Building Officials & Code Administrators)

M-1605.4.1 - Motor vehicle operation: In areas where moving and stationary motor vehicles operate for a period of time exceeding 10 seconds, the ventilation return air shall be exhausted. Additionally, areas in which stationary motor vehicles are operated for periods of time exceeding 10 seconds shall be provided with a source capture system that connects directly to the motor vehicle exhaust systems. Such source capture systems shall comply with section M-311.0: In motor vehicle repair areas, an exhaust system shall be provided to connect directly to the motor vehicle exhaust.

M-1602.1 General - The following words and terms ... definitions shown herein:

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.

Visit BOCA on the web. http://www.bocai.org