The challenge with high-purity cyclopentane-based, ( commonly referred to as just Pentane ) blowing agents is that they, along with most hydrocarbon fluids, are flammable. Handling flammable products safely requires increased knowledge and awareness of the hazards involved, proper equipment, and procedures to minimize the risks. A flammable liquid is described in National Fire Prevention Association (NFPA) Standard 30 (Flammable and Combustible Liquids Code) as a product that has a closed-cup flash point below 100°F. Rigid spray systems formulated with high-purity cyclopentane-based blowing agents will fall into this flammable category and thus require additional safety awareness, equipment, and procedures to reduce the risks when handling and applying these spray systems.
Exterior applications, such as on a roof, generally have sufficient ventilation to reduce the build up of flammable vapors. For interior applications, positive ventilation is essential in conjunction with vapor monitoring to ensure a safe work environment. Studies have confirmed that in urethane foam applications, fire risks are minimal once the blowing agent is preblended in the resin system polyol (B-side). This is because the evaporation and volatility characteristics are substantially reduced.