MR. BUILD UNIVERSAL MULTI FOAM B1 is quick setting single component polyurethane foam with fire retardant properties. It meets the extremely stringent requirements of DIN 4102 Part 1 for Construction Materials; Class B1 where fire ratings up to 240 minutes are achievable. Once cured, the foam can be cut, sawn or plastered over after only one hour providing the working temperatures (can and surfaces) are between +5 to +30oC, ideally 20oC. (Tested according to BS 476 part 22)