Correlation study in skin and eye irritation between rabbits and humans based on published literatures.

The purpose of this study was to investigate the correlations in skin and eye irritations between rabbits and humans using published international databases. We selected 60 and 56 compounds for skin and eye irritation, respectively. When the reactions were divided into irritation-negative or irritation-positive, including corrosion, similar reactions between rabbits and humans were detected for 53 compounds in skin irritation and 54 compounds in eye irritation, showing rates of agreement in skin and eye as 88% and 96%, respectively. These findings revealed that correlation in skin and eye irritations between rabbits and humans were high. However, corrosion was observed in rabbit skin treated with 14 compounds, 4 of which showed similar changes in humans, and in rabbit eyes treated with 9 compounds, 1 of which revealed similar changes in humans. These findings indicated that the incidence of corrosion was higher in rabbits than in humans. Our results showed that the data on rabbit irritations in the skin and eye were useful for identifying risk of irritation in human.

Evaluation for skin sensitization based on published literatures (existing information) of major PRTR designated chemical substances in Japan.

Of the 354 substances designated as class I under the Pollutant Release and Transfer Register (PRTR) law in Japan, we reviewed the sensitization data of the selected 144 substances and analyzed it from various aspects comparing human and animal data, determining the relationship between skin sensitization and chemical structure and comparing the various international organizations. Although most of them were expected to be hazardous substances, 49 out of the 144 substances lacked both human and animal sensitization data. Positive substances accounted for 69% and 42% of the substances for which sensitization data were available in the case of humans and animals, respectively. A correlation was observed between the chemical structures of the substances and sensitization, despite the relatively few substances examined in this study and the limited homogeneity of the collected data. In particular, epoxides clearly had sensitizing potentials and more than half of carboxylic esters or dicarboxyl anhydrides, aliphatic aldehydes, and aromatic compounds with at least two hydroxyl groups also had sensitizing potentials. Also, this study clearly demonstrated the lack of consistency across the sensitization assessment criteria adopted by different countries or among those adopted by the same country on the basis of different laws or administrative measures.