FAN BLADES IN POSITIVE-PRESSURE BLOWERS Produced by the Industrial Health and Safety Program, Occupational Health and Safety Branch, Ministry of Labour. Disponible en fran¨ais. HAZARD SUMMARY: Positive-pressure fans or blowers are used in the fire service to ventilate smoke and heat. Recently, a few minutes after a firefighter started a gas- powered positive-pressure fan to ventilate a room, parts of the fan blade assembly broke apart. Several pieces penetrated the protective screen on the front of the fan housing and lodged in the ceiling. AFFECTED FANS: Positive-pressure fans manufactured by Super Vacuum Manufacturing Company, Inc., Model 720G4, delivered before August 1992. These have 20 inch (51 cm) fan blades made of aluminum. LOCATION(S) AND SECTOR(S): Municipal and industrial fire services. SUGGESTED PRECAUTIONS: Section 25(1)(b) of the Occupational Health and Safety Act requires the employer to ensure that "equipment, materials and protective devices provided by him are maintained in good condition". All fans of this type should be inspected on a regular basis as recommended by the manufacturer. Fan assemblies that show cracks or other defects should immediately by taken out of service and returned to the manufacturer for repair. For more information, please contact Ed Gulbinas, P.Eng. at (416) 326-7931 or, toll-free in Ontario, at 1-800-268-8013.