RIFM, US EPA, Cosmetics Europe, and other stakeholders collaborate on inhalation TTC
The human nose is a highly sensitive organ that can detect a wide variety of odors in very small concentrations. Thus, it is not surprising that 99% of all fragrance ingredients fall below the most conservative inhalation Threshold of Toxicological Concern, or TTC. TTC is the level of exposure to a substance beneath which there is no concern for adverse effects.
Limited historical (pre-2010) data and no validated non-animal tests exist for evaluating local respiratory toxicity. Because of this, TTC plays a strategic role in helping scientists assess the safety of fragrance ingredients on the respiratory system. As scientists develop animal-alternative methods to assess respiratory safety, it is critical to scrutinize all the existing data to enhance their understanding.
That’s why, in 2020, Cosmetics Europe organized a workshop: Challenges Faced in Developing Inhalation Thresholds of Toxicological Concern (TTC) – State of the Science and Next Steps. Participants included the United States Environmental Protection Agency, the Fraunhofer Institute, Unilever, Procter & Gamble, and the Research Institute for Fragrance Materials (RIFM).
Scientific journal Regulatory Toxicology and Pharmacology has just published a collaborative report on the workshop written by several workshop participants, including RIFM Senior Scientist Nikaeta Sadekar, PhD, DABT.
“The report lays out the current status of the inhalation TTC,” Dr. Sadekar, who leads RIFM’s Local Respiratory Toxicology endpoint, explained. “As a greater interest in this area of science was identified at the workshop, we have initiated a collaboration with other participants to expand the chemical space, harmonize data evaluation criteria, and enhance the existing inhalation TTC limits based on appropriate subcategorization of the chemicals. These are important steps because they will help align the perspectives surrounding the application of exposure-based waiving as an important animal alternative aspect of local respiratory toxicity safety assessment.”