146 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS TABLE VII--SUBACUTE DERMAL STUDIES IN RA•mTS TREATED WITH SLS Summary of Histopathological Findings* (liver, kidney, heart, thyroid, adrenals, pancreas, skin, brain and bone marrow examined) Incidence, dose, mg./kg. Findings 0 6 60 150 Li yet Periductal inflammation Hematopoietic loci Slight fatty change Coccidial infection Kidney Focal chronic inflammation Heart Myocarditis Petechial hemorrhage o f myocardi um Subendocardial hemorrhage Thymus Involuted Thyroid Small colloid cyst Brain Focal collections of round cells around vessels, meninges and in gray matter Rare round cell focus (Encephalazoon) infection Skin Epidermal pustules with early ulceration Epidermal pustules without early ulceration Mild-acute and chronic inflammation in dermis Intraepidermal abscess 1 1 2 1 1 '1' 2 1 'l' .... 1 . . I 1 .. .. 1 2 2 .. 2 2 1 * Only positive findings shown. period) of a 25% solution were added to 1 in. cotton pads which were maintained in contact with intact and abraded skin of the abdominal area and held in place with cloth bandages around the entire trunk. Moderate to severe burns were reported with no mortality. These studies with SLS involved an absolute dosage of 1250 mg. independent of the body weight of the animal. The maximum grade of irritation reported was consistent with those seen in the present study. Although no comments are made by Olson et al. with respect to mor- tality, indicating that none died, the weight range of the rabbits is not given. The mode of application, namely introduction by saturation of a cotton pad, may also have played a role. CONCLUSION Central nervous stimulation including tremors, tonic-clonic convulsions, and respiratory collapse were seen following the administration of acutely toxic derreal doses of sodium lauryl sulfate to rabbits, rats and guinea pigs. The derreal L.D.•0 determined by 24-hour topical exposure of rabbits was

DERMAL TOXICITY OF SODIUM LAURYL SULFATE 147 580 4- 138 rag. per kg. Spinal transection in rabbits blocked all motor manifestations without effectively modifying the respiratory collapse. Subacute derreal administration over a 90-day period of approximately 1, 10 and 25% of the acute L.D.50 value failed to produce the acute symptoms or any other manifestations of clinical or dose-related tissue pathology. The data support the absence of a cumulative effect following repeated daily applications of sodium laury] sulGte. (Received September 25, 1963) REFERENCES (1) O. G. Fitzhugh and A. A. Nelson, y. •dm. Pharm. •dssoc. Sci. Ed., 37, 29 (1948). (2) K. J. Olsen, R. W. Dupree, E. T. Plomer and V. K. Rowe, 5 e. Soc. Cosmetic Chemists, 13, 469 (1962). (3) l.. C. Miller and M. l.. Tainter, Proc. Soc. Exptl. Biol. 3•red., 57, 261 (1944).