The Research Institute for Fragrance Materials' human repeated insult patch test protocol

Abstract With implementation of the dermal sensitization QRA approach for fragrance ingredients, IFRA/RIFM are recommending use of the RIFM standard human repeated insult patch test (HRIPT) protocol for generation of confirmatory human data for the induction of dermal sensitization in a normal human population. Details of this standard HRIPT protocol are provided in this paper. The study protocol consists of two phases-Induction and Challenge. In the Induction phase, patches treated with fragrance ingredients in 75% diethyl phthalate/25% ethanol are applied to backs of volunteers for 24 h. Following patch removal there is a 24-h rest period and volunteers are patched again at the same site. This procedure is repeated to achieve 9 applications over a 3-week period. There is an approximate 2-week rest period followed by a Challenge phase of a single 24-h patch application of test article applied to a naïve site on the back. Skin reactions at the naïve site observed at Challenge may be suggestive of dermal sensitization, and a Rechallenge is performed to confirm the nature of the reactivity. This study is designed to confirm the No-Observed-Effect-Level for induction of dermal sensitization in a normal human population

t4 Workshop Report: Integrated Testing Strategies (ITS) for Safety Assessment

Integrated testing strategies (ITS), as opposed to single definitive tests or fixed batteries of tests, are expected to efficiently combine different information sources in a quantifiable fashion to satisfy an information need, in this case for regulatory safety assessments. With increasing awareness of the limitations of each individual tool and the development of highly targeted tests and predictions, the need for combining pieces of evidence increases. The discussions that took place during this workshop, which brought together a group of experts coming from different related areas, illustrate the current state of the art of ITS, as well as promising developments and identifiable challenges. The case of skin sensitization was taken as an example to understand how possible ITS can be constructed, optimized and validated. This will require embracing and developing new concepts such as adverse outcome pathways (AOP), advanced statistical learning algorithms and machine learning, mechanistic validation and “Good ITS Practices”.JRC.I.5-Systems Toxicolog

Implementation of the dermal sensitization Quantitative Risk Assessment (QRA) for fragrance ingredients

a b s t r a c t Significant developments have recently been incorporated in the way dermal sensitization risk assessments are conducted for fragrance ingredients. Based on the RIFM Expert Panel's recommendation, RIFM and IFRA have formally adopted the QRA approach, refined for fragrance ingredients identified as contact allergens, as the core strategy for primary prevention of dermal sensitization to these materials in consumer products. This new methodology is a major improvement over the former approach because it specifically addresses the elements of exposure-based risk assessment that are unique to the induction of dermal sensitization, while being consistent with the principles of toxicological risk assessment. This methodology will be used to determine global fragrance industry product management practices (IFRA Standards) for potentially sensitizing fragrance ingredients, the first of which was implemented in May 2006 with the 40th Amendment to the IFRA Code of Practice. It contained the first four IFRA Standards based on the QRA, limiting the use of the materials for 11 individual product categories. One of the first four IFRA Standards based on the QRA was on the fragrance material citral. The basis for the acceptable exposure limits are presented in this paper