Non-ozone-depleting Foam Sealants

First they were produced with CFC-11 blowing agents. Then the CFCs were replaced with HCFCs, which are only 5%-10% as damaging to stratospheric ozone. Now several manufacturers of one-part polyurethane foam sealants are using hydrocarbon blowing agents or a mix of hydrocarbons and non-ozone-depleting HFCs.