Natural oils dry and harden by absorbing oxygen. Chemically, this is an “exothermic reaction” in which some heat is released.
This slight warming cannot be measured on painted surfaces. However, heat cannot extract from the cavities of oil-contaminated porous materials (sponges, insulating materials, polishing pads, grinding dust) or crumpled textiles, application rags and cleaning rags. Heat in turn favours the oxygen absorption of the oils, which leads to even more heat development. A chain reaction starts. Under certain circumstances, the material may self-ignite. This does not happen spontaneously or explosively, but first becomes noticeable through a typical very strong smell, then through smoke development. In some cases, inflammation may finally occur.
A process that normally takes several hours, but can sometimes take place after as little as an hour at high summer temperatures. (By the way, conventional alkyd resin coatings and glazes also show the same problem. Unfortunately, this characteristic cannot be “weaned off” from natural drying oils. The only way to avert this danger is to handle it carefully. Oil-soaked cloths, sponges and polishing pads should therefore be stored under airtight conditions immediately after work, for example in a tin can or glass with lid or in a bucket of water.
You will therefore find the following information on our product labels and in the product information: “Caution: Materials soaked with product, such as cleaning cloths, sponges, grinding dust, polishing pads with oil that has not dried through, must be stored airtight in metal containers or in water, and when spreading, ensure that no oil comes into contact with porous insulating materials, as otherwise there is a risk of spontaneous combustion due to the vegetable oil content.
The product itself is not self-igniting
– Store out of reach of children.
– Pay attention to possible natural substance allergies.
– The natural raw materials used can give off a typical product odour
Keep oil impregnated cloths fireproof after processing!