Temporary Heating and Fire Risks

Welcome back, let’s Build Smart & Build Safe! Temporary heating is a requirement for winter construction, but it introduces high-energy ignition sources into dynamic environments. Many companies treat "salamander" heaters or propane units as standard appliances rather than industrial hazards. Under OSHA 1926.154, temporary heating devices must be installed and maintained with strict adherence to fire prevention protocols.

The Clearance Standard

The primary cause of heater-related fires is the proximity of combustible materials. Radiant heat can ignite objects several feet away without direct flame contact.

• Minimum Clearance: Maintain a minimum of 3 feet of clearance from the sides and rear of the heater, and at least 6 feet from the discharge end, unless the manufacturer specifies a greater distance.

• Combustible Materials: This includes tarps/poly, dimensional lumber, trash, and chemical storage. Ensure all temporary enclosures (plastic sheeting) are securely fastened so wind cannot blow them into the heater.

The Dust Ignition Factor

Construction sites are inherently dusty environments. In winter, as buildings are closed in, the concentration of airborne and settled dust increases. Many companies overlook the fact that common construction dust—from wood, drywall, and insulation—is a combustible solid.

• Flash Fire Risk: High-velocity heaters can pull airborne dust through the intake and across the open flame, leading to a flash fire or "blowtorch" effect.

• Smoldering Hazards: Dust that settles on the hot exterior housing of a heater can smolder and ignite long after the crew has left the site.

• Protocol: Heaters must be placed in areas that are kept clean of sawdust and debris. If a task generates significant dust (e.g., floor sanding or drywall finishing), temporary heaters in that area must be shut down.

Fuel Handling and Stability

• Stability: Heaters must be placed on level, non-combustible surfaces. If a heater tips, the safety shut-off must be tested and verified to work instantly.

• Propane Storage: OSHA requires that LPG cylinders be stored outside of buildings. Even "empty" cylinders contain enough residual vapor to cause an explosion and must be treated as full.

• Refueling: Never refuel kerosene or oil-fired heaters while they are hot or in operation. The surface temperature of the heater can exceed the flash point of the spilled fuel.

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-The Safety Man