Reaction products of sulphuric acid, rock phosphate and humic acids, potassium salts

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Read-across data of the components of the submission substance or similar substances is available for skin sensitisation. CSP-TSP is closely related to the submission substance, as it contains the same the same humic acid - phosphate complex. The only difference is the presence of calcium sulfate as an additional constituent in CSP-SSP. Data on calciuim sulfate from a Guinea pig study are presented to confirm absence of sensitising properties for all constituents.

The following data is available for the similar substance CSP-TSP:

The objective of this study was to evaluate the potential of the test item to induce delayed contact hypersensitivity using the murine Local Lymph Node Assay (LLNA). A preliminary test was performed to define the test item concentrations for the main test. Two groups of two female mice received the test item by topical route to the dorsal surface of both ears (one concentration per ear) on days 1, 2 and 3 at concentrations of 5, 10, 25 or 50% under a dose-volume of 25 μL. The thickness of both ears of each animal was measured and the local reactions were recorded. In the main test, three groups of four female mice received the test item by topical route to the dorsal surface of both ears on days 1, 2 and 3 at concentrations of 10, 25 or 50% under a dose-volume of 25 μL. Negative (vehicle) and positive controls (α-hexylcinnamaldehyde (HCA)) were conducted. From day 1 to day 3 and on day 6, the thickness of the left ear of each animal was measured, except in animals of the positive control group, and the local reactions were recorded. Each animal was observed at least once a day for mortality and clinical signs. Body weight was recorded once during the acclimation period, and then on days 1 and 6. After 2 days of resting, on day 6, the animals received a single intravenous injection of tritiated methyl thymidine (3H-TdR). Approximately 5 hours later, the animals were sacrificed and the auricular lymph nodes were excised. The proliferation of lymphocytes in the lymph node draining the application site was measured by incorporation of 3H-TdR. The results were expressed as disintegrations per minute (dpm) per group and as dpm/node. The obtained values were used to calculate Stimulation Indices (SI). No unscheduled deaths and no clinical signs were observed in any animals. Body weight was unaffected by the test item-treatment. Alopecia was observed on day 6 in 3/4 females treated at 50%. No notable increase in ear thickness was observed at any tested concentration. The threshold positive value of 3 for the SI was reached in the positive control group. The experiment was therefore considered valid. No notable lymphoproliferation was noted with the test item at any tested concentration. Under the experimental conditions of this study, the test item did not induce delayed contact hypersensitivity in the murine Local Lymph Node.

Calcium sulfate:

Calcium sulfate was tested for skin sensitising properties in a OECD 406 study with Guinea pigs (GLP). Epicutaneous induction was performed with test substance concentrations up to 100% (0.4 g). The challenge was also performed by epicutaneous application of 0.4 g pure substance. Neither skin irritation nor signs of sensitisation were observed in any of the test animals. The test substance was not sensitising under the conditions of this study.

In conclusion, the submission substance is not sensitising to skin.

Migrated from Short description of key information:
The similar substance CST-TSP, which deviates in composition from the submission substance only by the absence of calcium sulfate as an additional constituent, is not sensitising to skin (in an LLNA). Calcium sulfate was negative in an OECD 406 study. Therefore, the submission substance is considered to be not sensitising to skin.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No information on and no indication of respiratory sensitisation is available.

Migrated from Short description of key information:
No information on and no indication of respiratory sensitisation is available.

Justification for classification or non-classification

Based on the data described above, the submission substance does not have to be classified for sensitising properties according to Regulation (EC) No 1272/2008.