Flash Point

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SoapSap

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I am confused about the meaning of the term "flash point" means in regards to essential oils and fragrance oils.

Is the flash point the temperature the heat point for when the fragrance will loose its scent, or does it mean it is at this temperature it could ignite. I cannot find any explanation for this.
 
The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture in air. It is important in air transportation due to air compression. At this temperature the vapor may cease to burn when the source of ignition is removed.

Any fragrance or essential oil with a flashpoint 141º F or less can only fly if a hazmat certificate is filed. Any fragrance or essential oil with a flashpoint under 100º F must have a hazmat certificate filed for ground. USPS has further restrictions pertaining to the quantity of oil that can go in one box. Do you remember years ago when a plane exploded in air over the Florida Everglades? I believe they found that it was due to items in the cargo area that were undocumented with a low flashpoint. After that the FAA really cracked down.

Flashpoint does not necessarily correlate with aromatic volatility. For example, there are many fragrances that have a lower flashpoint and perform wonderfully in bases with higher temperatures. This is because (assuming they are immediately and quickly incorporated into the base) the aromatics are trapped and they cannot molecularly move through the base.

There are some oils with a low flashpoint that have a weakened scent when added to hot bases. This is more related to the aromatic volatility than flashpoint. For example, Frankincense has a flashpoint of 95º F and is thought to be fairly strong stays very strong in products such as cp soap while orange oil has a flashpoint around 115º and it weakens fairly quickly and significantly

Taken from WSP site from a google search
 
Flash point is the temperature at which a combustible or flammable substance will burn if exposed to a spark. The flash point enters into safety during shipping and storage, because a low flash-point material in a fire can make the fire much worse. That is why there are often hazardous material charges or restrictions on shipping low flash point materials. When the material is mixed with other stuff, like soap for instance -- the flash point of that one ingredient does not apply to the whole.

Flash point can be used as a rough measure of how volatile a flammable/combustible substance is. Bear in mind that not all volatile substances are flammable or combustible, so flash point isn't an absolute measure of volatility. For example, water is not flammable or combustible, but it is volatile (evaporates easily). As another example, common soaping oils are combustible, but they do not evaporate easily at all.

Many people use the flash point as the temperature at or below which they can "safely" add fragrance to soap. I don't pay any attention to that -- the flash point temp in this context is pretty much meaningless. When mixed into the soap, the fragrance won't burn for one thing. For another, one shouldn't be handling any fragrance or other flammable substance when close to open flame. And finally, fragrance, even if it is below its flash point, is still going to evaporate -- the warmer the soap, the faster the evaporation. My goal, whatever the fragrance, is to add it at the coolest temperature I can manage.
 
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