There are some useful HSE documents on safe-working covering general work in audiovisual production, noise at work in music and entertainment, and the use of explosives and pyrotechnics in SFX – you can find the links to all of these on this page.
Firstly, here is the current version of Health & Safety in Audiovisual Production [pdf]. When using this, it may be worth checking that you have the current version
Then there’s this: Sound advice: Control of noise at work in music and entertainment. It’s a 2008 publication so the same advice applies – check you have the current version.
Finally, there’s ‘Special or visual effects involving explosives or
pyrotechnics used in film and television productions’ [pdf]. Again, same advice – it’s linked to from the same HSE page, so make sure you have the current version.