The U.S. 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 Expert Panel for Cosmetic Ingredient Safety. The 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 Expert Panel considered available new data on these ingredients and reaffirmed the above conclusion. It reaffirmed this conclusion in 2023.

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.

FDA Code of Federal Regulations for n-Butane and Isobutane

Code of Federal Regulations for Propane

Code of Federal Regulations for Isopentane

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.