Tetrapotassium hexacyanoferrate

Endpoint summary

Description of key information

In an LLNA skin sensitisation study, performed according to OECD/EC test guidelines, the read across substance sodium ferrocyanide was considered not to be a skin sensitiser, as the SI appeared not to be ≥ 3 when tested up to 50%.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Based on identical metal-cyanide complex species, the source substance sodium ferrocyanide and the target substance potassium ferrocyanide can be regarded as analogues, which implies that data from sodium ferrocyanide can be read-across to the target substance potassium ferrocyanide based on this information. The complete rationale can be found in the read-across report in section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

other: Read-across rationale

Positive control results:

The six-month reliability check with Alpha-hexylcinnamicaldehyde indicates that the Local Lymph Node Assay as performed at WIL Research Europe is an appropriate model for testing for contact hypersensitivity. See attached document 'Reliability check'.

Key result

Parameter:

SI

Value:

2.2

Test group / Remarks:

10%

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

25%

Key result

Parameter:

SI

Value:

2.7

Test group / Remarks:

50%

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 560, 285 and 697 DPM respectively. The mean DPM/animal value for the vehicle control group was 254 DPM.

Results Pre-screen test:

No irritation and no signs of systemic toxicity were observed in any of the animals examined. Variations in ear thickness during the observation period were less than 25% from Day 1 pre-dose values. White test substance remnants were present on the dorsal surface of the ears of both animals at 50%, on Days 1-3, which did not hamper scoring of the skin reactions.

Other results - main study:

No irritation of the ears was observed in any of the animals examined. White test substance remnants were present on the dorsal surface of the ears of all animals at 50%, on Days 1-3, which did not hamper scoring of the skin reactions.

No mortality occurred and no clinical signs of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. The body weight loss noted for some animals across the dose groups was considered not toxicologically significant since the changes were slight in nature and no concentration-related incidence was apparent.

The majority of auricular lymph nodes were considered normal in size, except for the nodes in one animal at 10, 25 and 50% which were larger in size. No macroscopic abnormalities of the surrounding area were noted in any of the animals.

Interpretation of results:

other: Not classified according to Regulation (EC) 2012/2008

Conclusions:

In an LLNA skin sensitisation study, performed according to OECD/EC test guidelines, the substance was considered not to be a skin sensitiser, as the SI appeared not to be ≥ 3 when tested up to 50%. This result can be read across to potassium ferrocyanide.

Executive summary:

An LLNA skin sensitisation study was performed according to OECD/EC test guidelines and GLP principles. The test substances was tested up to 50%. No mortality occurred, no clinical signs of systemic toxicity were observed and body weights and body weight gain of experimental animals remained in the same range as controls over the study period. No skin irritation was seen in any of the animals, most auricular lymph nodes were considered normal in size and no macroscpic abnormalities were noted. The SI values calculated for the substance concentrations 10, 25 and 50% were 2.2, 1.1 and 2.7 respectively.

Based on these data, sodium feroocyanide is not regarded as a skin sensitizer.

The result can be read across to the target substance, potassium ferrocyanide.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

An LLNA skin sensitisation study was performed with the read across substance sodium ferrocyanide according to OECD/EC test guidelines and GLP principles. Sodium ferrocyanide was tested up to 50%. No mortality occurred, no clinical signs of systemic toxicity were observed and body weights and body weight gain of experimental animals remained in the same range as controls over the study period. No skin irritation was seen in any of the animals, most auricular lymph nodes were considered normal in size and no macroscpic abnormalities were noted. The SI values calculated for the substance concentrations 10, 25 and 50% were 2.2, 1.1 and 2.7 respectively.

Justification for selection of skin sensitisation endpoint:
The study has been performed according to OECD and/or EC guidelines and according to GLP principles and has Klimisch reliability 1.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on these data, the target's analogue, sodium ferrocyanide is not regarded as a skin sensitizer. Therefore potassium ferrocyanide does not need to be classified for sensitising properties according to CLP Regulation (No) EC 1272/2008.