Potassium triboron pentaoxide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Two studies are available on the registered substance as manufactured investigating the skin sensitisation potential of the test material using the Buehler method. During the study reported by Carey (1993), 0.3 mL of 5% (w/w) test material in petrolatum was applied, to the shaved backs of 20 guinea pigs once a week for three weeks. Two groups of control guinea pigs were handled in the same manner but were not treated with the test material. Two weeks following the induction period, the treated and the group 1 challenge control animals received a challenge dose of 0.3 mL of 1% (w/w) test material in petrolatum. Seven days after the first challenge exposure, the treated and the group 2 challenge control animals received a re-challenge dose of 0.3 mL 1% (w/w) test material in petrolatum. All animals were scored for erythema 24 and 48 hours following the first and second challenge doses.

Following primary challenge, an increase in the mean severity of irritation was observed in induced versus irritation control animals at 24, but not at 48 hours. Three induced animals displayed erythema scores of 2 at 24 hours, but only one animal retained a score of 2 at the 48 hour scoring period. Following the second challenge, the enhanced dermal response observed in the single animal at first challenge was again observed at second challenge. An erythema score of 2 was maintained at both the 24 and 48 hour scoring periods. Since this animal consistently exhibited a grade 2 score throughout all scoring periods, it is possible that this animal was sensitised. Overall, dermal responses of irritation control and induced animals were similar at both the 24 and 48 hour scoring periods.

In the study reported by Morris (1997), 0.3 mL test material was applied, unchanged, to the shaved backs of 20 guinea pigs once a week for three weeks. Three groups of control guinea pigs were handled in the same manner but were not treated with the test material. Two weeks following the induction period, the treated and the challenge control animals received a primary challenge dose of 0.3 mL of 10% test material in mineral oil. Two weeks following primary challenge exposure, treated/re-challenge control group #1 animals received a re-challenge #1 dose of 0.3 mL 10% test material in mineral oil. Two weeks later, the treated/re-challenge control group #2 animals received a re-challenge #2 dose of 0.3 mL 10% test material in mineral oil. All animals were scored for erythema 24 and 48 hours following the first application of induction dose and following the primary challenge, re-challenge #1 and re-challenge #2 doses. The grading was repeated the following day. For reporting purposes, the first and second gradings were designated as 24 and 48 hour readings respectively.

Following primary challenge, the incidence of grade 1 responses in the test group (6 of 20) was compared to that of the naive control group (2 of 10). The incidence and severity of these responses in the test group were slightly greater than those produced by the naive control group suggesting that sensitisation may have been induced. A re-challenge was conducted to confirm the presence of sensitisation. Following re-challenge #1, the incidence of grade 1 responses in the test group (13 of 20) was compared to that of the naive control group (2 of 10). The incidence and severity of these responses in the test group were greater than those produced by the naive control group, however, individual animal data comparisons showed animals responding at challenge that did not respond at re-challenge indicating sensitization had not occurred. A second re-challenge was conducted to confirm these findings. Following re-challenge #2, there was now a grade 2 produced in the test group. The incidence of grade 2 responses in the test group (1 of 20) was compared to that of the naive control group (0 of 10). Additionally, there was an increased incidence of grade 1 reactions in the test group (5 of 20) over that of the naive control group (1 of 10). These data did not meet the 15% criteria for classification.

Both studies presented to assess the skin sensitisation potential of the test material were performed in line with GLP and to method equivalent to those outlined in accepted standardised guidelines with a high standard of reporting. Both studies were assigned a reliability score of 1 in accordance with the criteria for assessing data quality as outlined in Klimisch (1997) and were considered suitable for assessment as an accurate reflection of the test material.

Migrated from Short description of key information:
Orthoboric acid, potassium salt was tested as manufactured and determined not to be sensitising according to studies considered equivalent to OECD Guideline 406 and EU Method B.6. A supporting study using boric acid as read-across was also negative.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Regulation 1272/2008 and Directive 67/548/EEC, the substance does not require classification for skin sensitisation.