File:Pu foam.jpg

Summary
Pulyurethane foam, used as a "penseal" or "penetration seal", instead of an approved firestop in a cable penetration. The Browns Ferry Fire involved such a seal, except that each side of the foam was coated with a fire retardant. This photo was taken at a Canadian plant. The foam was subsequently removed (3 manhours/ft³) and replaced with a proper firestop.