Silicone, latex, and elastomeric firestop sealants protect against the spread of fire, smoke, and gas. Firestop sealants are available in caulk, putty, or foam cement forms. Latex-based sealants are economical, environmentally safe, and are available in a range of fire-retardant formulas. Some latex sealants are vulnerable to water and freezing temperatures. Elastomeric sealants are highly flexible, water resistant, and fast drying. Some firestop sealants are self-leveling for floor use or they are non-sag for ceiling applications.