Expanding Foam, Feature : Meets CA-25-4, UL Classified, Tested To ASTM E-84-04.

Boss ® 333 is a ready-to-use, multi-purpose, polyurethane foam that expands to three times its original volume on contact with air. The expanding action fills holes, cracks and gaps more completely than standard caulks. Boss® 333 has excellent insulting properties and adhesion to virtually all building materials. BOSS® 333 Polyurethane Expanding Foam meets CA-25-4, complies with EPA Method 24 and California Air Resource Board Method 310 and is UL Classified.