BIOSTOP® Firestop Gasket is a single component fire rated gasket for use with electrical boxes when addressing the "24 inch rule". It is mounted on the inside of the cover plate and installed at the same time as the cover plate, covering the opening and providing the necessary fire protection. When exposed to heat, BIOSTOP® Firestop Gasket's highly intumescent nature causes it to expand forming a char that will seal off the opening and prevent the spread of flames and limit the temperature rise on the unexposed surfaces. BIOSTOP® Firestop Gasket is applied by hand, does not take up volume in the electrical box and is a labor saving replacement for putty pads in normal applications. U.S Patent No. 6,207,085; 6,252,167 & 7,348,484.
BIOSTOP® Firestop Gasket is used when electrical boxes are installed in rated walls facing opposite directions and horizontally zontally separated by less than 24". BIOSTOP® Firestop Gasket can also be used as a solution for standard electrical boxes when the 100 square inch rule is violated. BIOSTOP® Firestop Gasket is UL tested and can be used with both metal and plastic cover plates. Tested conditions for one and two hours.