If you’re on massage forums for more than a few months, you’ll occasionally see something pretty scary: A picture of burnt sheets, and a post describing the smell of smoke followed by a quick evacuation. There are even news articles every year or two of building fires caused by massage linens. This issue is underdiscussed (other than by ABMP, which stays on top of it), despite it being a concern specific to our industry, and despite it being something we can mitigate! So, let’s discuss.
To start, what the heck is happening? What we’re talking about here is spontaneous combustion. That’s where there’s no spark or other ignition source, but material still manages to accumulate enough heat to set it aflame. This happens to massage linens because oil oxidation is an exothermic reaction. As oxygen shacks up with oil molecules, a small amount of heat is released. This leaves you with stubborn oil stains (the oil polymerizes, making it less soluble), and a bad smell — oxidized oil is rancid oil.