Posted By Paul Bellis Alan Start with HSE document Food sheet No 2, which gives general guidance, and also points you to further information. Notably the Institute of Chemical Engineers guide to Dust Explosions. http://www.hse.gov.uk/pubns/food2.htm Also try this link to a univerity web site that gives an overview of the problem http://www.chemeng.ed.ac...01/webpage/deh/deh2.html Try this site for information on companies that provide pressure relief door panels and disks http://www.powderandbulk.../air/explosionrelief.htm good luck