A study of skin and eye irritation in the rabbit due to different sources of some cosmetic raw materials (Part II).

Summary Different lots of a number of oils used in cosmetics were subjected to different storage times, analysed and their effects on rabbit eye and skin were assessed following the official French methods. The scoring system diverged slightly from the official method and was described in Part I (1). All products were tested pure in the eye test without rinsing and no corneal involvement was found. Slight congestion of the iris and conjuctivae was noted. The products showing the worst (slightly irritant) score were one sample each of avocado oil and ethyl esters of turtle oil. The highest score on the primary cutaneous irritancy test (slightly irritant) was that for the volatile hydrocarbon solvents which also gave an oedematous reaction. On dilution or on open test the reactions were negligible. The repeated application test was continued only for 8 weeks (instead of 90 days) and a histological examination was carried out on treated areas at the end of this period. The oils were applied pure and in aqueous emulsion - 10% or 2% where a severe reaction was observed. Of five samples of sweet-almond oil one showed a high degree of oxidation (peroxide value 35 meq kg(-1)). This sample did not give any significant adverse reaction whereas some irritation and vesicularisation was obtained with a sample of low peroxide value stored under nitrogen. Two of the four samples of avocado oils tested showed severe irritation and vesicle formation after 6 weeks application of the pure oil although no analytical differences were found to correlate with this result. A commercial sample of the unsaponifiable fraction of avocado oil (prepared by molecular distillation) showed severe reactions in the three rabbits treated with the pure oil, the study being terminated after 5 weeks.