Shop all FireStop products at McCally Tool and Supply including caulk, pipe collars, firestop plugs, and more. FireStop is a passive fire protection system designed to prevent the spread of fire, smoke, and heat through openings in fire-resistant building components like walls and floors. It typically consists of specialized sealants, intumescent materials, collars, or wraps that are strategically installed around penetrations like pipes, cables, and ducts, as well as along joints, to maintain a continuous fire-resistance rating and provide occupants with more time to evacuate.