The National Institute for Occupational Safety and Health recommends that all fire departments operating apparatus equipped with automatic slack adjusters (ASAs) immediately take the following actions to reduce the risk of firefighters being injured in an apparatus crash due to brake failure:

• Ensure that ASAs are not manually adjusted. 
• Establish procedures to ensure maintenance on fire apparatus is conducted as recommended in NFPA 1911, Inspection, Maintenance, Testing, and Retirement of In-Service Automotive Fire Apparatus. 
• Ensure maintenance is only performed by qualified technicians who meet NFPA 1071, Emergency Vehicle Technician Professional Qualifications. 

An automatic slack adjuster is a mechanical component of the air-brake system that adjusts brakes as necessary when the vehicle is in operation to compensate for wear in the brake shoes (drum brakes) or pads (disc brakes). When an ASA is found to be out of adjustment, it signifies the existence of a larger braking system problem that needs correction. Manual adjustment of ASAs should only be done by qualified technicians during installation or when absolutely necessary to move the apparatus to a repair facility.

In 2006, the International Association of Fire Chiefs warned the fire service of this potential problem following an investigative report released by the National Transportation Safety Board. While conducting an investigation of a recent apparatus crash-related firefighter fatality, NIOSH learned that fire departments may not fully appreciate the hazards related to manual adjustment of ASAs. NIOSH would like to renew efforts to bring this to the attention of all U.S. fire departments, firefighters, and fleet-maintenance departments who are tasked with preventive maintenance or operation of apparatus equipped with ASAs. The manual adjustment of ASAs may contribute to unexpected brake failure on fire apparatus. When an ASA is found to be out of adjustment it signifies the existence of a larger problem with the braking system that needs to be corrected immediately. Vehicles found to have ASAs that are out of adjustment should be taken out-of-service immediately until corrective brake service is completed.

Further, the NTSB has recommended, and NIOSH agrees, that all drivers of fire apparatus equipped with air brakes must undergo training and testing to demonstrate proficiency in the inspection and operation of air-braked vehicles. Such training should emphasize that manual adjustment of automatic slack adjusters is dangerous and should not be done, except during installation, or in an emergency situation when it is absolutely necessary to move the vehicle to a repair facility.