Hi

We found an old fire extinguisher (1959) in a shed and are thinking about cleaning and restoring it to make it into a lamp. It says 'chemical foam' on the label, also 'Type F.L 3' and there is still some liquid in it. I feel that we should empty it before handling and using it in the house. I once read that some of these chemicals can be carcinogenic and/or toxic. What would you recommend?

Thanks for your help!

The outer container is just an alkaline solution of water, sodium bicarbonate and a foaming agent/stabiliser such as saponin, liquorice or turkey red oil. Whilst you shouldn't drink it it's not really that dangerous.

The inner container is a water based solution of aluminium sulphate which is mildly toxic and can cause severe eye damage (and damage to metal surfaces) but isn't really deadly.

Whilst the chemicals will have degraded over time, they will still react, producing foam under pressure and the cylinder is likely to be in poor condition so just to be safe do not empty it by setting it off to discharge.

Carefully remove the head anti clockwise, if after the first couple of turns there is a hiss through the vent holes, then there is pressure inside (unlikely though) so stop until the hissing has stopped before unscrewing further.

The contents can't go into the water table or normal street drains so should go down the foul waste for treatment i.e. the toilet, but not together and I'd flush a clean bowl after flushing the first solution before adding the second & flushing.

To see your actual model of extinguisher being used as intended watch this (it's at the end):