Document 2jkV3Qw1m4vGqqXwpzGN760r

ESSO RESEARCH AND ENGINEERING COMPANY MI5I1ICAL RKSKa KCH l>:VISION' -- p. o. BOa 45, LINDEN, N. J, 07036 April 3, 1967 Dr. J. Wesley Clayton, Jr. E, 1, duPont de Nemours and Co., Inc. Haskell Laboratory for Toxicology and Industrial Medicine Wilmington, Dels. 19898 Dear Dr. Claytons Last December we had some correspondence regarding the sensitization potential of Disperse yellow 23. Although jou had no experimental data, manu facturing experience gave no indication of sensitization. Some work which we have done gave a rather persistent feeling that there might be a sensitization potential, at least with regard to evoking a positive response in persons who may already be sensitized to some other chemicals. We have just completed a brief skin test, and I thought you might like to know. Of the results. Fifteen subjects who are known to be sensitive to paraphenyletie diamine were patched on the upper back with samples of the color, as well as some other materials. The patches were approximately one-half inch square and, remained in contact for 72 hours. The test sites were read immediately upon removal of the patch and 96 hours later. A scoring scale of 0, +, 1+, 2-f, 3+> and 4+ was used. Fourteen of the 15 subjects gave a 2+ or 3+ response to paraphenylene diamine, and the fifteenth gave a 4+ response. Disperse Yellow 23 evoked a response of 1+ to 4+ in 13 of the-15 subjects. We, therefore, feel fairly confident that under the conditions of these experiments Disperse Yellow 23 can evoke a sensi tization response in persons who are already known to be sensitive to para phenylene diamine. Sincerely yours. RAS:bsn R. A. SCALA, PhD RECEIV APR 4 1967 HASKELL LABORATORY xerox copies to JAZ, DBH, JWC, 4/12/67. Bjd