SKIN PROPERTIES OF TAIWANESE WOMEN 303 Table IV Moisture Content of Each Skin Type (unit: a.u.) Skin type 1 2 3 4 5 6 Section 1 102 ___ 6 97 + 6 91 +-- 11 95 + 3 99 + 9 93 + 10 Section 2 113 + 12 104 + 5 98 --- 15 107 + 2 105 + 12 104 + 11 Section 3 109 + 6 104 -+ 5 100 +-- 113 97 + 8 106 ___ 3 107 --- 9 Section 4 114 + 4 104 --- 8 100 + 16 100 __+ 8 112 + 10 103 + 10 Section 5 111 + 6 108 + 9 104 + 13 101 ___ 8 111 + 5 103 + 11 Section 6 107 --- 7 102 + 8 96 +-- 15 96 --- 9 103 + 8 101 +__ 14 Section 7 104 + 8 106 + 5 97 --- 12 95 + 13 110 --- 6 95 --- 60 Section 8 62 --- 26 66 --- 22 70 + 19 76 + 9 70 --- 33 69 + 80 Section 9 55 + 28 57 + 19 71 --- 27 73 --- 9 68 + 28 71 --- 15 Section 10 90 --- 11 84 + 11 90 + 11 83 + 10 93 + 10 83 + 13 Section 11 105 + 11 100 --- 11 106 --- 16 97 + 12 94 --- 23 98 --- 13 Section 12 103 + 9 98 --- 8 100 + 13 100 ___ 11 104 --- 6 94 + 8 Table V The Probability of Dehydration in Different Sections of the Face Skin type 1 2 3 4 5 6 Dehydrated Section 1 0% 0% 9% 0% 8% 0% Sections 3&5 0% 0% 9% 0% 0% 0% Sections 6&7 0% 0% 9% 0% 8% 20% Section 8 10% 25% 36% 33% 66% 40% Section 9 20% 38% 45% 33% 75% 40% Section 10 20% 25% 9% 0% 33% 20% Section 11 0% 0% 0% 33% 0% 0% Very Dehydrated Sections 8&9 50% 38% 18% 33% 0% 0% the effect of weather. We chose somewhat different criteria: that dehydrated skin has a moisture content between 50 and 80 a.u. and that very dehydrated skin has a value be- low 50 a.u. at a temperature of 22-25øC and a relative humidity of 75%. The criteria were determined by a panel of ten members who observed the skin of young Taiwanese women in daytime in spring. The probability of dehydration for each part of the face is listed in Table V for each skin type. The lower cheek (sections 8 and 9 in Table V) is the driest area of the face. Surprisingly, some young women's noses (about 20%, the average of section 10) are also a dehydrated area. Since we mentioned above that the nose is usu- ally very oily, it is thus not true that oil can seal moisture in the skin (2). LIPID CONTENT AND MOISTURE CONTENT OF THE NECK Compared with the face, the skin of the neck is an area of lower lipid content. The ex- perimental results are listed in Table VI. Note that the more oily the face, the higher the lipid content of the neck. Oily skin types (type 1) have the highest lipid content, and oil-depleted skin types (type 6) have the lowest value. Comparing the front of the neck with the rear, the lipid content is slightly higher, except for skin type 6. The mois-

304 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table VI Lipid Content and Moisture Content of the Neck Skin type 1 2 3 4 5 6 Lipid content (unit: •tgcm -2) Section 13 Section 14 Moisture content (unit: a.u.) Section 13 Section 14 96 --- 30 58 + 15 61 ___ 16 54 + 14 29 +- 22 17 + 10 77 + 36 45 + 20 46 + 15 43 +_ 24 24 _+ 14 33 --- 17 169 --- 10 102 ñ 8 105 -+- 8 96 --- 5 97 + 19 102 ___ 10 82 _+ 10 98 + 10 99 --- 16 94 + 13 85 + 23 91 -+ 10 ture content of the front of the neck was also found to be slightly higher than that of the rear neck. On the other hand, the moisture content of the neck was independent of skin type. Similar values of moisture content were found, as shown in Table VI. CONCLUSIONS 1. The lipid content of the face is in the range of 4-254 ptgcm -2 for young Taiwanese women. There are six skin types, including oily skin (20%), oil-depleted skin (10%), and oily T-zone combination skin (22%). 2. For partially oily combination-skin type, the T-zone is still the most oily area. The nose has the greatest tendency to be oily. Eighteen percent of women of skin type 3 have oily cheeks or an oily area around the eyes. 3. The moisture content of the face is between 23 and 147 a.u. Different skin types have a similar value. The lower cheek gives the lowest value of moisture content. Thus, the moisture content depends on the particular area of the face, not on the amount of oil secretion. Therefore, skin type is mainly determined by lipid content. 4. Some young Taiwanese women (about 20%) had a dehydrated nose, which is usually a very oily area. This is evidence that oil has no influence on diffusional water loss in the skin. 5. The lipid content of the neck is lower than that of the face, but a more oily face is as- sociated with a higher lipid content of the neck. Different skin types have similar moisture contents for the neck. A comparison was made between the front and rear of the neck. It showed that both the lipid content and the moisture content of the front were slightly higher than those of the rear neck, except for the lipid content of one skin type (the delipided skin type). REFERENCES (1) R. Wolf eta/., The effect of smoking on skin moisture and on surface lipids. Int. J. Cosmet. Sci., 14, 83-88 (1992). (2) K. Walas, Ed., ReM Bea•ty ReM Women: A Workbook for &lahing the Best of Your Own Good Looks (Master- Media Press, New York, 1992). (3) C. Jackson, Ed., Co/or Rle Beautify/Rlake•p Book (Ballantine Press, New York, 1988). (4) S.C. Place, Ed., The Art and Science ofProj•ssiona//Vlake•p. (Milady Press, New York, 1990). (5) L. Nogueira and D. Gabrielle, New techniques to assay skin care products, Dr•g Cosmet. Industry, 46-48 (Sept. 1988). (6) A.M. Kligman, Regression method of assessing the efficacy of moisturizing, Cosmet. Toilerr., 93, 27-35 (1978).