220 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 3. Comedogenic Grade 4. Enlarged follicles containing copious amounts of loosely arranged horny material resulted from applications of Grape Seed oil. (x 70) existence of large coinedones resulting from applications of potent acnegens, such as coal tar. Although this scoring system is similar to others (7-8), Mills and Kligman (12), using a four-point scale to evaluate comedogenic effects of detergent products, assigned a "ten" grade to effects produced by coal tars. In agreement with Kligman and Katz (15), we found naked eye assessment to be unreliable and judged comedogenic activity solely by microscopic evaluation. Table IV Comedogenic Activity of Esters of Fatty Acids Chemical Comedogenic Test Sample Trade Name Supplier Grade Decyl Oleate Ceraphyl-140 Van Dyk & Company, Inc. 3 Isodecyl Oleate Ceraphyl-140A Van Dyk & Company, Inc. 1 Octyl Palmitate Ceraphyl-368 Van Dyk & Company, Inc. 2-3 Isopropyl Palmitate Westwood Chemical 3 Myristyl Myristate (50% in Mineral Oil) Ceraphyl-424 Van Dyk & Company, Inc. 0-I Isopropyl Myristate (50% in Propylene Glycol) Wickenol IO1 Wickhen Products, Inc. 3-4 Glyceryl Stearate Tennessee Eastman Com- (50% in Mineral Oil) Myverol 18-05 pany 2 Kessler Division of Armour Isocetyl Stearate Chemical Corporation O-1 Propylene Glycol Isostearate Emerest-2389 Emery Industries, Inc. 3-4 Isopropyl Isostearate Emerest-2310 Emery Industries, Inc. 4 Isopropyl Linoleate Ceraphyl-lPL Van Dyk & Company, Inc. 4-5

COSMETIC INGREDIENT COMEDOGENICITY 221 Figure 4. Comedogenic Grade 5. Isopropyl Linoleate produced large quantities of densely-packed keratin which surrounds several pustules within this dilated follicle. ( 70) In evaluating comedogenic potential, most investigators selected a two-week exposure period. To eliminate occasional questionable test results, a three-week period of applications was deemed more appropriate. In addition, our observations coincide with other investigators (15,19) who found that the follicular response approached maxi- mum levels at this time. Since there appeared to be no consistent correlation between surface epidermal hyperplasia and morphological changes within the follicle, this criterion was ignored in the assignment of comedogenic grades. For our investigation, we selected a cross section of lanolin ingredients widely used by the cosmetics industry. Lanolin consists of a highly complex mixture of esters of high Table V Comedogenic Activity of Surfactants Chemical Comedogenic Test Sample Trade Name Supplier Grade Sodium Lauryl Sulfate Maprofix Onyx Chemical Company 0 (10% Aqueous) Sodium Lauryl Sulfate Maprofix Onyx Chemical Company 0 (5% Aqueous) Ammonium Lauryl Sulfate Sipon-L22 Alcolac, Inc. 0 (10% Aqueous) Octoxynol-9 Triton X-100 Rohm & Haas Company, Inc. 0-1 (50% Aqueous) Polysorbate 20 Tween 20 ICI Americas, Inc. 0 (1% Aqueous)