Many times it is very easy for people to get confused about the term that is usually used in the same sentence as essential oils and that is Volatile Oils.This is somewhat misleading. Sorry but none of around here came up with these terms, we just have to live with them. This question came up in relationship to someone saying that you have to be careful about using essential oils that might end up on clothing that might end up ending up in a dryer.
Volatile means that they evaporate easy when it is discussed in essential oil circles or in any thing aromatherapy. Combustible means that the substance can explode easy. EO"S just evaporate. I have heard some people say that if you Yadda Yadda with the oils they will explode. I have tried and tried to get them to explode or combust. I have failed at that task. In theory I can see if you buy a bottle of oil for say a buck or two from some discount joint, that is nothing more than just a synthetic or made from a crude imitation of a.. essentially an gasoline..of some sort. Those might explode or combust based on what they are made of, but decent oils....I think it is next to impossible to have them do so in a dryer, I would even go on to say impossible. If too much EO is used it could in theory mess with coloring on some types of clothing but beyond that, I would like to smoke what those people are smoking, on those days when you need to escape into fantasy land. Lol.
I would like to suggest that the type of combustion that they are attributing this issue to is due to spontaneous combustion due to having something wet in and among some dry cloth and not allowed to ventilate. This creates a condition of heating that leads to combustion. This is a typical thing that can happen when the rug rats will throw a wet towel in the corner and then throw other clothes on top of it. It can"t air out and to make a long story short leads to a fire. The only element of contribution the EO"S had to a fire as stated in the article is a wet substance creating heat leading to a condition of a fire starting. If it happens to a dryer in action, it is usually traced to the lint and heat, a condition that will ignite at a lower temperature than day a wet towel in a kids bedroom. Most of the time if you have a dryer "issue" with a fire, it is because of the air not being allowed to ventilate and the essential oil connection is just a consequence of another issue and not directly related to the essential oil directly.
Now most people will have washed an article of clothing or for that matter any cloth before it goes in the dryer. The soap used would cut out any trace of the essential oil during the wash cycle. So if a piece of cloth goes in the dryer by having by passed the washer, well that is not a normal situation and it could lead to other problems, like setting a stain, and on and on. You can always create a situation where some weird thing could happen such as.. well if you apply enough heat to anything, it will catch on fire or even explode. But that is not with in the normal parameter of normal use. All of this discussion is based on the normal use of essential oils, cloth and a dryer.