Abstract
Hydroquinone (HQ) has enjoyed a wide popularity as a skin de-pigmentation agent. The usage of HQ in Japan has increased due to the effect of the 2001 Deregulation of Cosmetics Act. The efficacy of HQ has been widely reported but there are few actual tests verifying the safety of its usage. We have decided to evaluate and test the safety of HQ as a cosmetic ingredient. The tests conducted were based on the accepted methods as dictated by the Japan Guidance for Cosmetics Safety Evaluation. The tests were nine in total. 1. Acute Oral Toxicity. 2. Primary Skin Irritation. 3. Cumulative Applications. 4. Skin Sensitivity. 5. Photo Toxicity. 6. Photo Sensitivity. 7. Ocular Irritation Levels. 8. Reverse Mutation using micro-organisms. 9. Human patch tests. The results of our testing were twofold; HQ has a potential for skin sensitivity problems and weak to mild primary skin irritation.
