Fire Resistant Expanding PU foam. A high performance, polyurethane expanding foam, fire rated and tested to BSEN 1366-4 and BS476 Part 20 (the most stringent test for fire rated products).
Bond It B1 Fire Resistant Foam – Gun Grade (Pack of 12) - Fire Seals Direct
Everbuild B1 Hand Held Expanding Fire Rated Foam, Pink, 750 ml : Amazon.co.uk: DIY & Tools
12 x B1 Fire Rated Foam Soudal Gun Grade Expanding Insulating PU Foam 750ml : Amazon.co.uk: DIY & Tools
Bond It B1 Fire Resistant Foam – Gun Grade - Fire Seals Direct
Everbuild Fire Foam B1 750ml - Frank Key
Fischer 45300 B1 Fire Rated Expanding Foam - Gun Grade 750ml from Lawson HIS
750ml B1 Fill & Fix Exp PU Foam Hand 1 EA - Screws & Fasteners