Having delivered a mini teach session for the PTLLS certificate on Fire Safety recently, I was questioned about my use of Heat as one side of my triangle. It emerged that the learner questioning this had recently undertaken fire awareness training in his workplace at which, Heat was replaced by Ignition.

Whilst I can understand the logic of ignition, I was taught years ago that heat was a prerequisite of the ignition process.

Obviously, if I need to deliver this training session again, I need to ensure that I am up to speed with the latest train of thought in this area.

If anyone would like to comment on this subject, I would be grateful for your input.

Paul

I carry out industrial gases safety training as part of my job and the fire triangle is a key part of that. The fire triangle I use has heat. I am not aware of whether heat or ignition is preferred by trainers these days. However I think whichever you use you should get the group to give you their thoughts on what ignition (or heat) actually means in the fire triangle and tease this out a bit during the training. Maybe we should use "ignition or heat". The following are some of the things I mention in training.

Ignition - does not need to be a naked flame or spark but can be heat. when using gases like hydrogen which has a low ignition temperature this gas can ignite just by the heat generated when "snifting" a cylinder. Oxygen for example during adiabatic compression can cause ignition of particles in the gas stream. There are a number of pyrophoric cases that will ignite on contact with air, but this is maybe going too deep for a general fire safety presentation.

Heat - I am not so sure that heat is required for ignition - if you think about static electricty a spark is generated without any heat, although there is going to be some heat in the spark.

Interesting topic and hope this is of some use. It will be interesting to see what other forums members views on this topic are

That's confusing because it no longer will be a triangle????

There is a difference in the triangle between

a) an actual fire, when taking away one of the three sides; air,heat or fuel will stop the fire and

b) starting a fire when you need air, fuel and ignition energy which is not necessarily heat.

Tetrahedron of fire has been a common reference term for a long time

Shaun, in my experience it was usually the initial three sided triangle followed by the addition of the senior officer. The side most difficult to control and remove was always the senior officer.

Just a small point Chris - bleve's are not necessarily LPG incidents. Bleve's can occur with non-flammable gases.

I meant to say about the chain reaction that dry powder extinguishers interfere with this which is how they work.

Must say I miss the lively debate from the old forum. I reckon, a number of people have been put off by the initial log in problems etc

D

Shaun, just a small answer to your small point, I did know that but wanted to be brief. Thanks anyway.