Whilst I cannot help directly you may get some assistance from this organisation;

http://www.playengland.org.uk/playsafetyforum

They also produced a document entitled 'Managing risk in play provision', amongst others.

Other postings are very near the reality as far as children are concerned as I have had ~5 broken wrists 1 broken ankle, 1 broken arm and 2 index finger damage all hospitalised and RIDDOR on children only very very recently but as yet not a dickybird from the HSE so there may be some politics involved NB: The HSE is the enforcer in most cases as the EHO's only enforce some areas in none council schools


The Play England doc is OK however you need to read the detail as I find overall its back to basic risk assessment and somebody willing to put their name to a decision as there are disclaimers therein, its not law and the doc will not protect a head if protection is needed


Each council should have in place child experts who should be able to help