Potassium tetrafluoroaluminate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

No skin sensitisation studies are available on potassium tetrafluoroaluminate. However, Article 13 of the REACH legislation states that, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i. e., applying alternative methods such as in vitro tests, QSARs, grouping and read-across. Data are available on a structural analogue, multiconstituent aluminium potassium fluoride. Multiconstituent aluminium potassium fluoride is a multi-constituent substance containing ca. 70% of KAlF₄and ca. 30% of higher homological penta- and hexafluoroaluminic acids, K₂AlF₅and K₃AlF₆. The presence of these higher homological salts is, however, not expected to alter significantly the physico-chemical and toxicological properties of multiconstituent aluminium potassium fluoride in comparison to potassium tetrafluoroaluminate.

A guideline-compliant Magnusson Kligman Test (GPMT) is available on multiconstituent aluminium potassium fluoride (NOTOX, 1998). 1% aqueous carboxymethyl cellulose was used as a vehicle.In the main study, ten experimental animals were intradermally injected with a 2% concentration of multiconstituent aluminium potassium fluoride and epidermally exposed to a 50% concentration of the test substance at day 8 (for 48 hours). Five control animals were similarly treated, but with the vehicle (1% aqueous carboxymethyl cellulose) only. Approximately 24 hours before the epidermal induction (day 8) exposure all animals were treated with 10% SDS. Scabs, erythema and/or necrosis were noted at the injection sites and no skin reactions, except for some small scabs, were noted at the epidermal application sites. Two weeks after the epidermal application all animals were challenged (epidermal exposure) with a 50% test substance concentration and the vehicle using a dressing (24 hours exposure). At 24 and 48 hours after removal of the dressing, the treated sites were assessed for challenge reactions. After challenge, no skin reactions were observed in treated and control animals. Based on the results of the study, potassium tetrafluoroaluminate is considered to be not sensitising to skin.

Migrated from Short description of key information:
In a Magnusson Kligman Test with guinea pigs with the read-across candidate multiconstituent aluminium potassium fluoride no skin sensitisation was observed. Based on this, potassium tetrafluoroaluminate is also considered to be not sensitising to skin.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

No airway sensitisation studies are available on potassium tetrafluoroaluminate. However, Article 13 of the REACH legislation states that, in case no appropriate animal studies are available for assessment, information should be generated whenever possible by means other than vertebrate animal tests, i. e., applying alternative methods such as in vitro tests, QSARs, grouping and read-across. Data are available on a structural analogue, multiconstituent aluminium potassium fluoride. Multiconstituent aluminium potassium fluoride is a multi-constituent substance containing ca. 70% of KAlF₄ and ca. 30% of higher homological penta- and hexafluoroaluminic acids, K₂AlF₅and K₃AlF₆. The presence of these higher homological salts is, however, not expected to alter significantly the physico-chemical and toxicological properties of multiconstituent aluminium potassium fluoride in comparison to potassium tetrafluoroaluminate.

The airway sensitisating potential of an aerosol of multiconstituent aluminium potassium fluoride was studied in Brown Norway rats (TNO, 2004a). One group of 6 female rats was exposed to a target concentration of 100 mg/m³ multiconstituent aluminium potassium fluoride for six hours a day for 5 consecutive days (sensitisation phase). Approximately 14 days later these animals were exposed to the same concentration of multiconstituent aluminium potassium fluoride for 30 min (challenge phase). Two control groups, also of 6 female BN rats each, were used. One group was sensitised only, the other group was exposed to air during the sensitisation phase and challenged to 100 mg/m³ for 30 min approximately 14 days later. The day after challenge hyperresponsiveness to methacholine was tested in all animals; two days after challenge the animals were necropsied. To examine possible allergenicity of multiconstituent aluminium potassium fluoride, total and specific IgE levels, breathing pattern and frequency during challenge, hyperresponsiveness to methacholine one day after challenge, and histopathology of the respiratory tract and bronchoalveolar lavage fluid measurements two days after challenge were carried out.

No treatment-related abnormalities were observed. Also no changes in body weight gain and organ weights were noted.

No increases in specific IgE levels or treatment-related changes in cholinergic hyperresponsiveness upon methacholine challenge were noted. There were also no changes in breathing frequency and pattern during challenge, suggesting that multiconstituent aluminium potassium fluoride is not a respiratory tract sensitiser. Repeated inhalation of multiconstituent aluminium potassium fluoride induced histopathological changes in the nasal passages, larynx, and lungs. Focal olfactory epithelial degeneration, necrosis and regeneration were observed in the nasal passages. In the larynx, there was a focal granulomatous inflammation. In the lungs, alveolar bronchiolisation and typical alveolar macrophage accumulations were seen. Sensitised animals exhibited a significantly increased percentage of neutrophils and a significantly decreased percentage of ofeosinophils in bronchoalveolar lavage fluid. The tested concentration of 100 mg/m³ for both sensitisation as well as the challenge phases was therefore considered sufficiently high enough in view of the observed histopathological and bronchoalveolar lavage fluid changes. Based on the results of the study, potassium tetrafluoroaluminate is considered to be not sensitising to the respiratory tract.

Migrated from Short description of key information:
The airway sensitisation potential of an aerosol of multiconstituent aluminium potassium fluoride studied in Brown Norway rats revealed no effects, i.e., multiconstituent aluminium potassium fluoride does not induce respiratory tract sensitisation. Based on these results, potassium tetrafluoroaluminate is also considered to be not sensitising to the respiratory tract.

Justification for classification or non-classification

Based on read-across from multiconstituent aluminium potassium fluoride, potassium tetrafluoroaluminate is not a skin and respiratory tract sensitiser. In accordance to Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, classification is not necessary for sensitisation.