As an electrician I spend a great  amount of time working on emergency lights, I have a concern it involves the batteries that are fitted to most new emergency lights . On various internet sites Li-ion batteries are shown exploding when set on fire.

I have worked on various sites where the corridor lighting consists of multiple maintained emergency lights containing these batteries and I wonder are rules in place to protect people from the explosive reaction and/or is there no acknowledged risk.

The reason for fires in Li-ion batteries, the explosion risk is not a major consideration, is design faults or using the incorrect charging equipment, consequently providing the EL units are BSI approved there should be no problems. 

Emergency light fittings almost invariably use NiCad batteries anyway, so aren't really a concern, I'd be interested to know whose brand is using Li-ion