Potassium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulphonate

Endpoint summary

Description of key information

A guinea pig maximization test (GPMT) and local lymph node assay (LLNA) were conducted on PFBSK+. The results of the studies were:

 

Non-sensitizing in a guinea pig maximization test conducted according to a method similar to OECD 406.

 

Non-sensitizing in a local lymph node assay conducted according to OECD 429.

The dermal sensitization potential of the test article was evaluated in the Maximization Test using male and female Hartley guinea pigs. This study was performed in accordance with GLP (1997). The study design was based on Maximization Test methods described in Dermatotoxicology, 5 ed. (1996). The test article was prepared in Sterile Water for Injection (vehicle for intradermal induction) or petroleum jelly (vehicle for epidermal induction and challenge) just prior to each dosing procedure. The test group (10 males and 20 females) received intradermal induction injections of 0.1 ml/site of a 1:1 mixture of Freund’s Complete Adjuvant (FCA):vehicle, 125 mg/mL test article in vehicle, and 125 mg/mL test article in 1:1 FCA/vehicle. A control group (5 males and 10 females) received the same induction treatment with the exclusion of test article. The epidermal induction of sensitization was conducted under occlusion with 0.5 g test article in vehicle (test group) one week after the intradermal induction and 24 hours after pre-treatment with 10% sodium dodecyl sulfate. The control group did not receive any treatment during the epidermal induction. Two weeks after epidermal induction the control and test animals were challenged by epidermal application of 33.33% test article and vehicle only under occlusive dressing. Skin reactions were evaluated at 24 and 48 hours after removal of the dressing. One week after the first challenge, the males were rechallenged in a similar manner. The females were not rechallenged due to a lack of positive results. Positive controls (2-mercaptobenzothiazole and hexyl cinnamic aldehyde) were recently tested to confirm the validity of the experimental technique. Three control group males and one test group male were found dead on Days 9-11. These deaths were not associated with test article treatment. No erythema or edema was observed at any site in either the control or test article group females following the first challenge. No erythema or edema was observed at any site in either the control or test article group males following the rechallenge (0% responders). Based on the results this study, there was no evidence of skin sensitization following treatment with the test article.

 

The dermal sensitization potential of the test article was evaluated in a modified mouse local lymph node assay (LLNA/IMDS) using female NMRI mice (6/dose). The study was performed in accordance with GLP (1997). The study design was based on OECD 429 (2002). The test material was formulated in PEG 400 immediately before exposure. The test material was formulated immediately before each administration in PEG 400. The test item in formulation (25 µL/ear) was applied epicutaneously onto the dorsal part of both ears of the animals at 0, 3, 10, and 30%. Treatment was repeated on three consecutive days (d1, d2, and d3). Animals were anaesthetized by inhalation of carbon dioxide and sacrificed one day after the last application (day 4). Weight and cell count of the lymph nodes, ear swelling (day 1 and 4), ear weight (day 4), and body weights (day 1 and 4) were recorded for each animal. No changes in body weight were observed in any dose group. No increase in simulation indices for cell counts or for weights of the lymph nodes were seen. The “positive level” of 1.3 for cell count index was never reached or exceeded in any dose group. The “positive level” of 2 x 10-2mm increase for ear swelling was also not reached or exceed in any dose group. Positive levels are defined based on the NMRI mice used for the study and such levels have to be calculated for each strain of mice individually. No increases of ear weights could be determined when compared to controls. A concentration of 30% was the NOEL for the parameters investigated in this study. Based on the results of the study, there was no evidence of skin sensitization following treatment with the test article.

Justification for classification or non-classification

Criteria for classifying as a dermal sensitizer are not met.