The common astringent known as witch hazel, derived from the Hamamelis virginiana plant, is a popular ingredient in toners and skincare products. A frequently searched safety question is whether witch hazel is flammable, and the answer, for most products found in drugstores, is a definite yes. The flammability is not inherent to the plant extract itself but is introduced during the manufacturing process.
Flammability Depends on Preparation Method
The flammability of witch hazel depends almost entirely on how the final product is prepared. The standard commercial extract, often labeled “Witch Hazel USP,” is typically made using steam distillation that requires the addition of alcohol as a preservative and solvent. This commonly results in a solution containing 14% to 15% ethyl alcohol by volume.
A true witch hazel hydrosol, or “flower water,” is a product of steam distillation that contains the plant’s volatile oils and water but no added alcohol. This preparation is non-flammable and is generally not classified as hazardous. However, these pure hydrosols are less common in general retail than the alcohol-containing version. Consumers should check the ingredient label carefully; if alcohol or ethanol is listed, the product must be handled with caution.
Why Alcohol Content Matters
Commercial witch hazel’s flammability is directly linked to its ethanol content, which is classified as a flammable liquid. Ethanol, or ethyl alcohol, is highly volatile, meaning it easily evaporates and forms ignitable vapors, which are the real source of a fire hazard. The potential for a solution to ignite is measured by its “flash point,” the lowest temperature at which its vapors will mix with air to create a combustible mixture.
Standard witch hazel, with its 14% alcohol concentration, has a flash point of approximately 109.6°F (43.1°C). This temperature is low enough that the product can catch fire if exposed to a spark, open flame, or high heat.
Necessary Safety and Storage Practices
Because most witch hazel products are flammable liquids, specific precautions must be taken to prevent fire hazards. The most important rule is to keep the container away from all sources of ignition, including gas stoves, lit candles, cigarettes, and any hot surfaces.
Witch hazel should be stored in a cool, dry, and well-ventilated area, ideally at room temperature. Excessive heat should be avoided as it can cause the alcohol to evaporate faster, increasing the concentration of flammable vapors in the air around the product. Ensure the container is tightly sealed when not in use to prevent vapor buildup in the storage area. If a spill occurs, the area must be ventilated immediately, and all ignition sources must be eliminated before cleanup begins.