Home improvers who use linseed oil as part of their furniture projects are being warned about fire risks after a recent incident in which a pile of cloths began to spontaneously combust.
The incident, which happened at a home in the Daventry area last month, involved a pile of linseed oil-soaked cloths which had been used earlier in the day. They were folded up and put away, but then a chemical reaction happened, which caused them to smoke.
Northamptonshire Fire and Rescue Service (NFRS) was called to a bad smell of smoke in the property and the source was found to be box of smouldering cloths with the remnants of linseed oil on them.
For this reason, NFRS want to raise awareness about the safe disposal of cloths used to apply linseed oil.
Linseed oil can be used in a variety of ways but it is often used by people who want to treat their garden furniture.
When linseed oil is exposed to air and comes into contact with oxygen, a chemical reaction can be caused, creating heat – this is known as an ‘exothermic reaction’.
Linseed and some other oils generate heat at a faster rate during this process, so this could cause a cloth soaked in the oil to heat up.
The heat has to be able to escape at a faster rate than this reaction happens – otherwise it could mean the temperature eventually becomes high enough for the cloths to combust.
Lisa Bryan, Prevention, Safeguarding and Partnerships Manager at NFRS, said: “We wanted to raise people’s awareness of this incident simply because, although thankfully rare, it is a risk many people don’t really know about.
“Most people think of fires being started by obvious flames so when they tuck linseed oil-soaked cloths away somewhere, having them catch fire or start to smoulder is probably the last thing they will be expecting.
“I hope people will take note of our safety warning and really think about how they can safely dispose of these kinds of oily cloths, after carrying out DIY projects.”
Tips to safe disposal of materials used to apply linseed oil:
• The fire will only happen if there is the right balance of oxygen to enable the reaction to happen, but not enough circulating air to allow the heat to quickly escape. For this reason, it is recommended that linseed oil-soaked cloths are hung on a clothesline where air movement can help remove heat
• Do not store oil soaked cloths inside a building
• Soak the cloth in water and seal in a plastic bag before disposal in your rubbish bin
• Store in an airtight (preferably metal) container
• Please note, this reaction can also happen with some other types of oil – particularly when on radiators or other hot surfaces
• Please avoid getting linseed oil on clothing or any other cloth materials as these would pose the same risk as the rags used in the work itself
Fire Risk Assessment (worked example for House in Multiple Occupation (HMO)) (PDF 389KB)
