Powerfoam and TriggerFoam are one-part polyurethane expanding foams that set and cure into their final form by reacting to moisture and humidity present in the air. Their exceptional ability to bond allows Powerfoam and TriggerFoam to be applied to various building elements including the surfaces of concrete, brick, block, wood, steel, aluminum and other miscellaneous metals. Powerfoam and TriggerFoam are safe to use, containing no CFCs. As they are being dispensed, Powerfoam and TriggerFoam have a neutral odour. Cured foam is physiologically harmless.