Hydrogenated Castor Oil
What is it?
Hydrogenated Castor Oil, also known as castor wax, is derived from castor beans (Ricinus communis), which is typically a liquid at room temperature, that has been processed by adding hydrogen to make it more stable and raises its melting point so that it is a solid at room temperature. It is odourless and insoluble in water.
Historically, ancient Egyptians used castor oil as fuel for their lamps. Castor oil has also been used as a lubricant in machine and aircraft engines, and is added to certain paints, dyes and varnishes as well. Ingestion of pure castor oil works as a laxative to treat constipation.
What does it do?
Hydrogenated Castor Oil is a hard, waxy substance with a unique structure. It works with the other oils and waxes in the antiperspirant base to give the stick a firm but spreadable consistency. In all cases, because hydrogenated castor oil is insoluble in water, it is not readily washed away.
How is it made?
The castor oil is expeller pressed from the beans of the castor plant (Ricinus communis) and then purified by heat and filtration. As mentioned, the oil is a liquid at room temperature. The process of hydrogenation adds saturation to the oil, which increases the melting point and results in the hydrogenated oil being a solid at room temperature. The process of hydrogenation requires that the oil be heated under pressure in the presence of a nickel catalyst. The nickel is then reclaimed and reused for environmental reasons.
What are the alternatives?
The synthetic polymers (polysiloxanes), also known as silicones, are very commonly used as an alternative for their ability to provide an easily applied and water resistant product. Other materials that can be used for this purpose in personal care products specifically include synthetic waxes, petroleum waxes, or other ethoxylated oils, which would not meet our Stewardship Model.
Is this the right option for me?
Hydrogenated Castor Oil has a long history of safe use in personal care products.
Tom's of Maine recognizes that no two people are alike, and even with naturally derived ingredients, some individuals may develop an allergic reaction that is unique to them. As with any product, be sure to discontinue use if you experience discomfort or other indications that the product may not be appropriate for your individual body chemistry.