Assessment of the risk of respiratory sensitization from fragrance allergens released by air fresheners

Abstract

Consumers using air fresheners are exposed to the emitted ingredients, including fragrances, via the respiratory tract. Several fragrances are known skin sensitizers, but it is unknown whether inhalation exposure to these chemicals can induce respiratory sensitization. Effects on the immune system were assessed by testing a selection of five fragrance allergens in the respiratory local lymph node assay (LLNA). The probability and extent of exposure were assessed by measuring concentrations of the 24 known fragrance allergens in 109 air fresheners. It was shown that the most frequently used fragrances in air fresheners were d-limonene and linalool. In the respiratory LLNA, these fragrances were negative. Of the other tested chemicals, only isoeugenol induced a statistically significant increase in cell proliferation. Consumer exposure was assessed in more detail for d-limonene, linalool, and isoeugenol by using exposure modeling tools. It was shown that the most frequently used fragrances in air fresheners, d-limonene, and linalool gave rise to a higher consumer exposure compared with isoeugenol. To evaluate whether the consumer exposure to these fragrances is low or high, these levels were compared with measured air concentrations of diisocyanates, known human respiratory sensitizers. This comparison showed that consumer exposure from air fresheners to d-limonene, linalool, and isoeugenol is considerably lower than occupational exposure to diisocyanates. By combing this knowledge on sensitizing potency with the much lower exposure compared to diisocyanates it seems highly unlikely that isoeugenol can induce respiratory sensitization in consumers using air fresheners.

• Air fresheners
• fragrance allergens
• inhalation exposure
• respiratory LLNA
• respiratory sensitization

Acknowledgements

We thank Anja Redjosentono-Maat of the NVWA for the assessment of the levels of the fragrance allergens in the air fresheners. For technical assistance during the animal experiments, we acknowledge Jolanda Vermeulen, Liset de la Fonteyne, Arja de Klerk, Eric Gremmer, and Bert Verlaan of the RIVM. We thank Miriam Gerlofs, Paul Fokkens, and John Boere of the RIVM for their input in the experimental design for the inhalation experiments and for performing the inhalation exposures. For biotechnical support in the animal experiments, we thank the biotechnicians of the Institute for Translational Vaccinology. We are grateful that Prof. Dick Heederik of the Institute for Risk Assessment Sciences of the Utrecht University and Dr. Anjoeka Pronk of TNO-Innovation for Life for critically reading our manuscript and provided us additional information on their studies on diisocyanate exposure.

Supplementary material available online

Supplementary table.