What Is It?
Butane, Isobutane and Propane are colorless and odorless gases. Isopentane is a liquid. In cosmetics and personal care products, these ingredients are used in the formulation of shaving cream, cleansing products, hair conditioners, and makeup.
Why is it used in cosmetics and personal care products?
Butane, Isobutane, Propane and Isopentane are volatile substances derived from petroleum and natural gas. These ingredients are used in cosmetics and personal care products as a replacements for chlorofluorocarbons, or CFC propellants, some of which have been shown to have negative effects on the environment.
The Food and Drug Administration (FDA) has reviewed the safety of Butane, Isobutane and Propane and has placed these ingredients on the list of direct food substances affirmed as Generally Recognized As Safe (GRAS). Isopentane has been approved as an indirect food additive for use in the manufacture of foamed plastics. The safety of Butane, Isobutane, Propane and Isopentane has been assessed by the Cosmetic Ingredient Review Expert (CIR) Panel. The CIR Expert Panel evaluated scientific data and concluded that Butane, Isobutane, Isopentane and Propane were safe as a cosmetic ingredients under present practices of concentration and use. In 2002, the CIR Expert Panel considered available new data on these ingredients and reaffirmed the above conclusion.
More safety Information:
CIR Safety Review: Since Butane, Isobutane, Propane and Isopentane are used predominantly as aerosol propellants, inhalation toxicity testing rather than dermal toxicity has been emphasized. Many studies have been conducted on the anesthetic effects of these ingredients. It is believed, however, that these observations have little relevance to the use of these ingredients in cosmetics and personal care products, because of the brief and low level exposures involved in their use.
As aerosols, Butane, Isobutane, Propane and Isopentane are greatly diluted in air when discharged and it is estimated that, as propellants, they would remain on the skin no longer than 10 seconds. Because they evaporate quickly, these ingredients, even in foam products would not remain in contact with the skin longer than 10 seconds. Such a short period of contact makes the absence of sensitization, phototoxicity, and photosensitization studies unimportant. Furthermore, exposure standards have already been set by the National Institute for Occupational Safety and Health (NIOSH) and most of the substance is volatilized before it can come in contact with the skin.
Butane, Isobutane, Propane and Isopentane may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.
More Scientific Information:
Butane, Isobutane, Propane and Isopentane are low molecular weight alkanes. Butane, also called n-butane, is the unbranched alkane with four carbon atoms, while Isobutane is the branched alkane with 4 carbons. Propane is the unbranched alkane with three carbon atoms. Isopentane the a branched alkane with five carbons. These ingredients are used as a propellants in cosmetics and personal care products. Low molecular weight alkanes are highly volatile and have low solubility.
Find out more about the regulation of Food Additives by the Food and Drug Administration