[The evaluation of the irritating and sensitizing effects of benzalkonium chloride]

The aim of the study was to determine the threshold irritating effect of benzalkonium chloride on the rabbit's skin and eye, and its sensitizing effect on guinea pigs. The study was performed according to the OECD guidelines modified by Krysiak. As a threshold concentration of benzalkonium evoking slight inflammatory reaction on the skin in a single, closed exposure and in multiple, open exposure, the following values were adopted for its aqueous solutions: > 0.5-1%, and 05% respectively. Following the eye administration of 0.01% and 0.05% of benzalkonium aqueous solution a weak irritating and rapidly reversible effect was revealed. The study performed on guinea pigs indicated a sensitizing effect of 0.5%, 0.1% and 0.05% benzalkonium aqueous solutions. The effect differed depending on the concentration used. The evaluation covered the proportion of sensitized animals, the nature and intensity of dermal reaction, as well as peripheral blood eosinophil and basophil tests. The results showed that 0.1% benzalkonium aqueous solution is an optimum concentration for monitoring the sensitizing effect in humans being in contact with this substance.