Hydroxycitronellal: A survey of consumer patch-test sensitization

The potential of the fragrance material hydroxycitronellal to elicit human sensitization reactions or induce hypersensitivity was evaluated by analysing patch-test data for a variety of household and personal care products and fragrance blends containing hydroxycitronellal. Data from tests on hydroxycitronellal itself were also included. Data from a total of 11,638 patch tests containing hydroxycitronellal and involving approximately 9,300 subjects were evaluated. No reactions attributable to hydroxycitronellal were elicited as a result of exposure to the initial patch in any of the tests. The only reported reactions that could possibly be interpreted as elicitation of pre-existing sensitization to hydroxycitronellal occurred in a single test of one fragrance blend in which three persons reacted after multiple patching. However, follow-up tests in this one study did not consistently show reactivity to hydroxycitronellal. Induction of sensitization to hydroxycitronellal appears to be dependent on the exposure concentration. Sensitization to hydroxycitronellal appears to be induced primarily at exposure concentrations greater than 5% but one induction by 0·3% hydroxycitronellal in a fragrance blend was reported. No induced reactions occurred in 9,223 tests on consumer products. These observations provide valuable information regarding the safety of the use of hydroxycitronellal in consumer products.