Hi, welcome to the site.
This thread will help show you which buttons to look out for when making a new thread and these are a few ideas on the sources you could look into.
Health and Safety Executive (HSE)- COPPA and COSHH
Department for Education and your own Local Authority website/early years department
EYFS (Early Years Foundation Stage)
NCB
Child Accident Prevention Trust (CAPT)
St John Ambulance
Standards labelling -
on ROSPA
This thread also shows how others have approached this criteria
http://www.silkysteps.com/forum/showthread.php?t=14262
Page 135+ of this level 3 handbook Unit 027 / Unit CYP 3.4 sources of current guidance for planning healthy and safe environments
Best wishes