Carbon monoxide and diesel smoke are considered to be hazardous materials by the Occupational Safety and Health Administration (OSHA). Carbon monoxide is the leading cause of accidental poisoning deaths in the United States, while diesel exhaust has been shown to cause cancer. If higher than allowable levels of contaminants are detected in the work environment, heavy fines can be imposed by federal or state authorities. Therefore, it is critical that maintenance facilities have adequate vehicle exhaust evacuation systems, both for worker safety and OSHA compliance. Clearing the air
The first step in protecting your work environment is to gather information on the engines and operating conditions in the facility. Make a list of the engine displacements in cubic inches or liters. Pick the maximum rpm at which the engines are tested in the facility. Determine if the vehicles are tested under load either on a dynamometer or by hydraulic testing. The foregoing information is necessary to define the exhaust requirements for the vehicles and provide the basis for creating an adequate system design. Other elements of exhaust evacuation design include:

• Fan selection

• System layout

• Duct sizing

• Points of vehicle exhaust connection

• Type of collection devices It is crucial that the fan is sized to evacuate more air than the vehicle exhausts. If the vehicle exhausts more than the system can handle, the exhaust gases will expand into the room and create a health hazard. If you have questions about the system requirements, it may be a good idea to have a vehicle exhaust system expert verify the correct exhaust requirements as well as determine duct and fan sizing. It is also important to have a system that is user friendly so that the operators use it regularly. There are many types of system arrangements and adapter configurations designed for different building and vehicle configurations. For existing systems, some simple modifications may make the equipment easier to use. There are many different tailpipe adapters available for a variety of vehicles. Make sure that there are adapters available that fit every tailpipe configuration, so the exhaust system is able to be used on all vehicles. Routinely look for leaks
  For facilities with existing systems, managers should perform routine checks of the exhaust system to ensure that it works properly and is in good condition. They should check the tubing for any holes or burns and verify that it is not collapsed. They should also verify that the tailpipe adapters are able to stay on the tailpipes during all test procedures. The fans should be checked for any excessive noise or vibration that may be due to worn bearings or improper balance. It is a good practice to physically feel the air suction at the adapter to all of the bays to make sure that the system ductwork is not blocked at any point. Employers should educate the employees of the effects of exposure to carbon monoxide and diesel exhaust. Employees should learn the symptoms of carbon monoxide poisoning: headache, nausea, weakness, dizziness, visual disturbances, changes in personality and loss of consciousness. Safety issues should always be of primary importance. Wherever engines are running inside buildings, the safety of technicians, office personnel and other individuals is the primary concern of trade unions, insurance companies, fire departments and OSHA representatives. Compliance with the regulations is necessary in every case. Chris Krahn is an engineering graduate of Indiana's Valparaiso University. Kit Navarre is a graduate of Michigan's Hillsdale College.