Posted By David A Jones You don't say whether you are looking at top tier or lower tier sites - the requirements are significantly different. For example for ones I have worked, the lower tier sites only required a few pages to cover the requirements of a MAPP, whereas the upper tier site safety reports ran to 2+ lever arch folders. In terms of guidance on content, I suggest you look on the HSE web site where you should be able to find links to documents outlining how they assess upper tier reports - including some specific to the type of hazardous substance present.