COMEDOGENICITY 325 Table I (continued) Ingredient Grade (0-5) Comedo. •- Irrit. :• Ingredient Grade (0 - 5) Comedo.•- Irrit.:• PEG 100 distearate 2 0 PEG 150 distearate 2 0 PEG 200 dilaurate 3 2 Laureth-4 5 4 Laureth-23 3 0 Steareth-2 2 2 Steareth- 10 4 3 Steareth-20 2 1 Steareth- 100 0 0 Oleth-3 5 2 Oleth-5 3 2 Oleth- 10 2 1 Oleth-20 1 0 Oleth-3 phosphate 2 2 Triacetin 0 0 PPG 5 Ceteth 10 phosphate 4 2 PPG 2 myristyl propionate 3 2 PPG 10 cetyl ether 3 1 PPG 30 cetyl ester 0 0 PPG 50 cetyl ester 0 0 PEG 78 glyceryl monococoate 0 1 PEG 8 castor oil 1 1 PEG 40 castor oil 0 0 Polypentaerythrital tetralaurate 0 0 IV. Waxes Candelilla wax 1 0 Carnuba wax 1 0 Ceresin wax 0 0 Beeswax 0- 2 * 0 Lanolin wax 1 0 Jojoba oil 0-2* 0 Sulfated jojoba oil 3 2 Emulsifying wax NF 0 0- 2' V. Thickeners Carboxymethylcellulose 0 0 Carboxypropylcellulose 1 0 Hydroxypropylcellulose 1 0 Magnesium aluminum silicate 0 0 Carbomer 940 1 0 Bentonite 0 0 Kaolin 0 0 Talc 1 0 PVP 0 0 VI. Oils* Cocoa butter 4 0 Coconut butter 4 0 Hydrogenated vegetable oil 3 0 Sesame oil Corn oil Avocado oil Evening primrose oil Mink oil Soybean oil Shark liver oil Cotton seed oil Peanut oil Olive oil Sandalwood seed oil Almond oil Apricot kernel oil Hydrogenated polyisobutane Castor oil Hydrogenated castor oil Chaulmoogra oil Babassu oil Squalane Maleated soybean oil Safflower oil Sunflower oil Mineral oil VII. Pigments D & C red #3 D & C red #4 D & C red #6 D & C red #7 D & C red #9 D & C red # 17 D & C red # 19 D & C red #21 D & C red #27 D & C red #30 D & C red #33 D & C red #36 D & C red #40 Ultamarine violet Iron oxides Carmine Titanium dioxide VIII. Silicones Simethicone Dimethicone Cyclomethicone IX. SteroIs Cholesterol Soya sterol Peg 5 soya sterol 3(1)** 0 3 0 3(2) 0 3 2 3(2) 3 0 3 2 3 2 2 0 2(1) 0 2 0 2(I) 0 2(1) 0 1 2 1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0-2 0 0 0 0 (continued)

326 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table I (continued) Grade (0-5) Ingredient Comedo. ? Irrit. $ Ingredient Grade (0 - 5) Comedo. ? Irrit. Peg 10 soya sterol 0 1 XlI. Miscellaneous Choleth 24 0 0 Octyl dimethyl PABA Sterol esters 0 0 Oxybenzone Phytantriol 2 2 Octyl methoxycinnamate Octyl salicylate X. Vitamins and herbs Acetone A & D additive 2 0 Tocopherol* 0- 3' 0- 3' Ethyl ether Tocopheryl acetate 0 0 Diethylene glycol Black walnut extract 0 0 monoethyl ether Papain 0 0 Ethylene glycol Chamomile extract 0 0 monomethyl ether Vitamin A palmitate 1-3' 1-3' (EGME) Panthenol 0 0 Xylene Lithium stearate XI. Preservatives and additives Magnesium stearate Methyl paraben 0 0 Zinc oxide Propylparaben 0 0 Zinc stearate Phenoxyethyl paraben 0 0 Triethanolamine Allantoin 0 0 Stearic acid: TEA Hydantoin Amoniomethylpropinate Sodium hyaluronate 0 0 Sodium PCA Chondroitin sulfate 0 0 Hydrolyzed animal protein Precipitated sulfur 0 0 Water-soluble sulfur 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 3 1 0 1 0 1 0 0 0 2 0 3 2 0 0 0 0 0 0 ? Comedogenicity or ability of test substance to produce follicular hyperkeratosis. $ Irritancy or ability of test substance to produce surface epithelial irritation. * Results depend on source of raw material. ** Parentheses indicate results using "reftned"oil. The higher ethoxylated derivatives with HLBs above 12 are more water-soluble and noncomedogenic and nonirritating (PEG 75 lanolin). Two of the lanolin derivatives studied require special comments: (1) The acetylated lanolin alcohols are both comedo- genic and irritating, not because of the acetylated lanolin but because of the cetyl acetate additive (Figure 1), and (2) PEG 16 lanolin (Solulan 16) is quite comedogenic and irritating, perhaps secondary to the combination of nonlanolin additives: ceteth-16, oleth- 16, and steareth- 16. Among the fatty acids and esters a similar analogy is found. The mid-chain-length fatty acids, such as lauric acid and myristic acid and its analogs cause follicle hyperkeratosis. As the molecular weight of the fatty acid becomes larger and the effective charge of the overall molecule is reduced, less follicular reaction is produced. When the fatty acid is esterified with a small- to mid-size alcohol, the combination becomes more potent than the fatty acid itself. The cousins of isopropyl myristate, such as myristyl myristate, isopropyl isostearate, isostearyl neopentanoate, butyl stearate, and decyl oleate, are all comedogenic (Figure 2). Also, when branched-chain fatty acids are used, the derivatives may be more comedogenic. Large molecular weight esters, such as behenyl erucate and cetyl palmitate, are not a problem.