I am looking for a source of advice advice on what type of tread coverings may or may not be suitable for the treads of a spiral staircase that is the sole escape route in 3 storey blocks of flats.

A vinyle specification that I have seen gave ots combustion products as

carbon monoxide and hydrochloric acid and advised

breathing apparatus with itd own air supplu for fire fighting.

Is there any website that covers the problem ?

Thanks for any suggestions.

This applies to any fire and more because as it is very likely there will be plastic products in the premises. This is why we say smoke kills, if the concentrations are heavy enough and advise people to escape as soon as possible when a fire threatens. Fire-fighters have to enter thick smoke and need to wear breathing apparatus with its own air supply it should not be necessary for the occupants as they should be clear before the smoke is too thick and toxic levels are reached.

This is why fire-fighters will always advise any person who has breathed in smoke to visit the hospital for a check-up.

There are also special requirements with regards to any flammable materials on escape routes.

You should read also the LACoRS guide

Harry