Spray Foam Equipment

Spray polyurethane foam (SPF) insulation is mixed in a rig that heats and pressurizes two chemicals and sprays them through a gun. Isocyanates in the mix can cause asthma and other illness, and the foam can burn fast. The equipment and the room both need control.

• Insulation Installers
• Contractors
• Other Trades

Hazards

• Isocyanates (MDI): irritate the lungs, eyes and skin and can cause lasting asthma after sensitization. See Isocyanates and Occupational Asthma.
• Other chemicals: amines, catalysts and flame retardants in the resin side.
• High-pressure and heated hoses that can burst or burn.
• Fire: uncured foam and spray overspray are flammable. Hot work near foam can start fires. See Hot Work Permits.
• Electrical and generator hazards with the rig. See Portable Generators.
• Heat stress in protective suits.

Rig safety

• Read the manufacturer's manual and SDS for the foam and the rig
• Keep drums upright, ventilated and temperature controlled; use proper transfer pumps
• Inspect hoses, fittings, pressure gauges and relief valves before each day; replace damaged parts
• Relieve pressure before servicing; lock out power. See Lockout/Tagout
• Ground the equipment and keep ignition sources out of the work area
• Keep an extinguisher nearby and know how to shut down the rig fast

Protecting people

• Wear a supplied-air respirator or full-face air-purifying respirator with organic vapor cartridges and particulate filters, as the plan and SDS require, along with fit testing and medical clearance. See Respiratory Protection and SCBA & Supplied-Air Respirators.
• Wear disposable coveralls, gloves, boots and eye protection that seal around the face. Isocyanates absorb through skin.
• Ventilate the work area and exhaust to the outside. Keep other trades out until the foam has cured and the re-entry time has passed.
• Post warning signs and block access. Occupants and pets should leave until it is safe.
• Do not spray over wet surfaces or in extreme temperatures against the instructions; this causes poor curing and odors.
• Wash up before breaks and after work. Do not eat in the area.

Last updated: October 8, 2026