Class 1.4s indicates that, in a fire, any effects should be restrained within the packaging - subject to the items being in standard initial packages. Some general info here: http://www.ribbands.co.uk/hazard-cat.html about the explosives categories and here http://www.bucksfire.gov...FFCA5/0/10_Fireworks.pdf relates to fireworks but will have similar requirements. Also some more from the West Yorks Fire Service: http://www.westyorksfire...f10acc1f54cc78a1182f.pdf 1. More detailed information can be found in the Health & Safety Executive’s publication HSG184 ‘Guidance on the handling, storage and transport of airbags and seat belt pr-tensioners’. ISBN 0 717615987 and the ‘Approved Code of Practice and Guidance for the Manufacture and Storage of Explosives’. - L139 ISBN 0 7176 2816 7. available free download: http://www.hse.gov.uk/pubns/books/l139.htm Unfortunately HSG184 has disappeared from the HSE website, an information leaflet remains: INDG280 but there is not much on bulk storage there. You may get help from the local fire advisor. Enjoy the reading.