Safety evaluation of gums and thickeners used in cosmetic formulations

Synopsis Safety tests have been carried out on gums and thickeners, continuing a study involving commonly used cosmetic ingredients (1, 2, 3, 4). The ocular and cutaneous tolerance tests have been conducted on the rabbit following the official French methods (5, 6) but with some complements or modifications (1, 2, 3, 4, 7). The test substances (listed in Table 1) were products from various suppliers and of different types and grades. None of the fifty samples tested provoked pathological lesions of the ocular mucous membrane; nevertheless, corneal irritation was noted with silicates, silica and bentonite, probably due to mechanical effect, when applied at relatively high concentration. The highest score on the primary cutaneous irritancy test (moderately irritant) was that for the gelled volatile hydrocarbon solvents. The repeated application test was continued for 6 weeks: no significant pathological reaction was observed. Only a slight intolerance was noted with the gels of volatile hydrocarbons and isopropyl myristate, but the irritant reactions were significantly reduced compared to those previously observed with the pure oils (1, 2). Consequently, based on these data, it can be concluded that the use of gums and thickeners involved in this publication presents no hazard for the skin.