Expert Panel for Cosmetic Ingredient Safety

Scientific and technical data supporting the safety of 237 alkyl ester ingredients as used in cosmetics products was thoroughly assessed by the Expert Panel for Cosmetic Ingredient Safety (formerly the Cosmetic Ingredient Review Expert Panel) in 2015. The Expert Panel concluded that the following were safe as cosmetic ingredients in the present practices of use and concentration when formulated to be non-irritating to skin:

• Arachidyl Behenate
• Arachidyl Erucate*
• Arachidyl Propionate
• Batyl Isostearate*
• Batyl Stearate*
• Behenyl Beeswax
• Behenyl Behenate
• Behenyl Erucate
• Behenyl Isostearate*
• Behenyl Olivate
• Behenyl/Isostearyl Beeswax*
• Butyl Avocadate
• Butyl Babassuate*
• Butyl Isostearate*
• Butyl Myristate
• Butyl Oleate*
• Butyl Stearate
• Butyloctyl Beeswax*
• Butyloctyl Behenate*
• Butyloctyl Candelillate*
• Butyloctyl Cetearate*
• Butyloctyl Oleate*
• Butyloctyl Palmitate*
• C10-40 Isoalkyl Acid Octyldodecanol Esters*
• C14-30 Alkyl Beeswax*
• C16-36 Alkyl Stearate*
• C18-38 Alkyl Beeswax*
• C18-38 Alkyl C24-54 Acid Ester*
• C20-40 Alkyl Behenate*
• C20-40 Alkyl Stearate
• C30-50 Alkyl Beeswax*
• C30-50 Alkyl Stearate*
• C32-36 Isoalkyl Stearate*
• C40-60 Alkyl Stearate*
• C4-5 Isoalkyl Cocoate*
• Caprylyl Butyrate*
• Caprylyl Caprylate
• Caprylyl Eicosenoate
• Cetearyl Behenate
• Cetearyl Candelillate
• Cetearyl Isononanoate
• Cetearyl Nonanoate*
• Cetearyl Olivate
• Cetearyl Palmate*
• Cetearyl Palmitate*
• Cetearyl Rice Branate*
• Cetearyl Stearate
• Cetyl Babassuate
• Cetyl Behenate*
• Cetyl Caprate
• Cetyl Caprylate
• Cetyl Dimethyloctanoate*
• Cetyl Esters
• Cetyl Isononanoate*
• Cetyl Laurate
• Cetyl Myristate
• Cetyl Myristoleate*
• Cetyl Oleate*
• Cetyl Palmitate
• Cetyl Ricinoleate
• Cetyl Stearate
• Cetyl Tallowate
• Chimyl Isostearate*
• Chimyl Stearate*
• Coco-Caprylate
• Coco-Caprylate/Caprate
• Coco-Rapeseedate*
• Decyl Castorate*
• Decyl Cocoate
• Decyl Isostearate*
• Decyl Jojobate*
• Decyl Laurate*
• Decyl Myristate*
• Decyl Oleate
• Decyl Olivate
• Decyl Palmitate*
• Decyltetradecyl Cetearate*
• Erucyl Arachidate*
• Erucyl Erucate*
• Erucyl Oleate*
• Ethylhexyl Adipate/Palmitate/Stearate*
• Ethylhexyl C10-40 Isoalkyl Acidate*
• Ethylhexyl Cocoate
• Ethylhexyl Hydroxystearate
• Ethylhexyl Isononanoate
• Ethylhexyl Isopalmitate
• Ethylhexyl Isostearate
• Ethylhexyl Laurate
• Ethylhexyl Myristate
• Ethylhexyl Neopentanoate*
• Ethylhexyl Oleate*
• Ethylhexyl Olivate
• Ethylhexyl Palmitate
• Ethylhexyl Pelargonate
• Ethylhexyl Stearate
• Heptyl Undecylenate
• Heptylundecyl Hydroxystearate
• Hexyl Isostearate
• Hexyl Laurate
• Hexyldecyl Hexyldecanoate*
• Hexyldecyl Isostearate
• Hexyldecyl Laurate
• Hexyldecyl Oleate*
• Hexyldecyl Palmitate*
• Hexyldecyl Stearate
• Hexyldodecyl/Octyldecyl Hydroxystearate*
• Hydrogenated Castor Oil Behenyl Esters*
• Hydrogenated Castor Oil Cetyl Esters *
• Hydrogenated Castor Oil Stearyl Esters*
• Hydrogenated Ethylhexyl Olivate
• Hydrogenated Ethylhexyl Sesamate*
• Hydrogenated Isocetyl Olivate*
• Hydrogenated Isopropyl Jojobate*
• Hydroxycetyl Isostearate*
• Hydroxyoctacosanyl Hydroxystearate
• Isoamyl Laurate
• Isobutyl Myristate*
• Isobutyl Palmitate*
• Isobutyl Perlargonate*
• Isobutyl Stearate*
• Isobutyl Tallowate*
• Isocetyl Behenate
• Isocetyl Isodecanoate*
• Isocetyl Isostearate*
• Isocetyl Laurate*
• Isocetyl Myristate
• Isocetyl Palmitate
• Isocetyl Stearate
• Isodecyl Cocoate
• Isodecyl Hydroxystearate*
• Isodecyl Isononanoate
• Isodecyl Laurate
• Isodecyl Myristate
• Isodecyl Neopentanoate
• Isodecyl Oleate
• Isodecyl Palmitate*
• Isodecyl Stearate*
• Isohexyl Caprate
• Isohexyl Laurate*
• Isohexyl Neopentanoate*
• Isohexyl Palmitate*
• Isolauryl Behenate*
• Isononyl Isononanoate
• Isooctyl Caprylate/Caprate*
• Isooctyl Tallate*
• Isopropyl Arachidate*
• Isopropyl Avocadate*
• Isopropyl Babassuate*
• Isopropyl Behenate*
• Isopropyl Hydroxystearate
• Isopropyl Isostearate
• Isopropyl Jojobate
• Isopropyl Laurate*
• Isopropyl Linoleate
• Isopropyl Myristate
• Isopropyl Oleate*
• Isopropyl Palmitate
• Isopropyl Ricinoleate
• Isopropyl Stearate
• Isopropyl Tallowate*
• Isostearyl Avocadate
• Isostearyl Behenate
• Isostearyl Erucate*
• Isostearyl Hydroxystearate
• Isostearyl Isononanoate
• Isostearyl Isostearate
• Isostearyl Laurate
• Isostearyl Linoleate
• Isostearyl Myristate
• Isostearyl Neopentanoate
• Isostearyl Palmitate
• Isotridecyl Isononanoate
• Isotridecyl Laurate*
• Isotridecyl Myristate*
• Isotridecyl Stearate
• Lauryl Behenate*
• Lauryl Cocoate*
• Lauryl Isostearate*
• Lauryl Laurate
• Lauryl Myristate*
• Lauryl Oleate
• Lauryl Palmitate
• Lauryl Stearate
• Lignoceryl Erucate*
• Myristyl Isostearate*
• Myristyl Laurate
• Myristyl Myristate
• Myristyl Neopentanoate
• Myristyl Stearate
• Octyldecyl Oleate*
• Octyldodecyl Avocadoate*
• Octyldodecyl Beeswax*
• Octyldodecyl Behenate*
• Octyldodecyl Cocoate*
• Octyldodecyl Erucate
• Octyldodecyl Hydroxystearate*
• Octyldodecyl Isostearate
• Octyldodecyl Meadowfoamate*
• Octyldodecyl Myristate
• Octyldodecyl Neodecanoate*
• Octyldodecyl Neopentanoate
• Octyldodecyl Octyldodecanoate
• Octyldodecyl Oleate*
• Octyldodecyl Olivate
• Octyldodecyl Ricinoleate
• Octyldodecyl Safflowerate*
• Octyldodecyl Stearate
• Oleyl Arachidate*
• Oleyl Erucate
• Oleyl Linoleate
• Oleyl Myristate*
• Oleyl Oleate
• Oleyl Stearate*
• Propylheptyl Caprylate
• Stearyl Beeswax
• Stearyl Behenate*
• Stearyl Caprylate
• Stearyl Erucate*
• Stearyl Heptanoate
• Stearyl Linoleate*
• Stearyl Olivate
• Stearyl Palmitate
• Stearyl Stearate
• Tetradecyleicosyl Stearate*
• Tetradecyloctadecyl Behenate*
• Tetradecyloctadecyl Hexyldecanoate*
• Tetradecyloctadecyl Myristate*
• Tetradecyloctadecyl Stearate
• Tetradecylpropionates*
• Tridecyl Behenate*
• Tridecyl Cocoate*
• Tridecyl Erucate*
• Tridecyl Isononanoate
• Tridecyl Laurate*
• Tridecyl Myristate*
• Tridecyl Neopentanoate
• Tridecyl Stearate

* Not reported to be in current use. Were these ingredients to be used in the future, the expectation is that they would be used in product categories and at concentrations comparable to others in this group.

The Expert Panel previously conducted a safety assessment of cetyl esters, the International Nomenclature Cosmetic Ingredient (INCI) name for a synthetic wax composed of a mixture of esters of saturated fatty acids and fatty alcohols with carbon chain lengths between 14 and 18. The Expert Panel concluded that cetyl esters (a mixture of cetyl palmitate, cetyl stearate, myristyl myristate, myristyl stearate, cetyl myristate and stearyl stearate) is safe as used in cosmetics. Since cetyl esters is a subset of the broader group of cosmetic ingredients (alkyl esters) that are the reaction products of fatty acids and alcohols, the Expert Panel expanded its earlier safety assessment to include all alkyl esters in 2013, which are currently described as cosmetic ingredients based on similarities in molecular structures, physical and chemical properties, and usage in cosmetics.

The data available for the 2015 review by the Expert Panel that supported the safety of the alkyl esters included single-dose and repeated-dose toxicity, data on how the body metabolizes these ingredients (i.e., toxicokinetics), reproductive and fetal development toxicity, potential to alter genetic material (i.e., genotoxicity), cancer-causing potential (i.e., carcinogenicity), skin and eye irritation, and allergic skin reaction and sun-induced allergic reaction studies. In addition, in separate assessments, the Expert Panel previously concluded that many of the individual constituents of alkyl esters (i.e., the alcohol and/or the acid) are safe as used in cosmetics.

The consensus of the Expert Panel was that earlier safety assessments had determined that dermal penetration of long-chain alcohols is predicted to be low, so they extended that information to suggest that dermal penetration for alkyl esters is likely to be even lower. The Expert Panel also noted that some alkyl esters can enhance the penetration of other ingredients through the skin. Manufacturers should exercise caution in formulating cosmetic products that may contain these ingredients in combination with any ingredients whose safety was based on their lack of dermal absorption data, or when dermal absorption is a concern.

The Expert Panel acknowledged that some alkyl esters may be formed from plant-derived or animal-derived acid or alcohol constituents. Since pesticide residues and trace levels of heavy metals may be present in botanical ingredients, they stressed that the cosmetics industry should continue to use the necessary procedures to limit the amount of such impurities in an ingredient before blending them into cosmetic formulations.

Additionally, the Expert Panel considered the dangers of using animal-derived ingredients, namely the transmission of infectious agents (e.g., bovine spongiform encephalopathy [BSE]). While tallow is animal derived and may be used in the manufacture of some alkyl ester ingredients, the Expert Panel noted that the tallow used in cosmetics products is highly processed for purification. Tallow derivatives are even more processed for purification. The Expert Panel agreed with determinations by the U.S. Food and Drug Administration (FDA) that tallow derivatives used in cosmetics do not pose a risk of transmitting infectious agents.

The Expert Panel also noted the potential for skin irritation with the use of products formulated using some alkyl esters and specified that products must be formulated to be non-irritating to skin.

U.S. Food and Drug Administration (FDA)

Isoamyl laurate and butyl stearate are approved as direct food additives for use as a flavor substance adjuvant (21CFR172.515). Many alkyl esters are approved as indirect food additives, as listed in the Code of Federal Regulations Title 21.

Alkyl Esters reviewed by the Expert Panel are all listed in the EU’s Cosmetic Ingredient Database (CosIng) and may be used safely under the rules governing cosmetic products in the Cosmetics Regulation of the European Union.