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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in chemico
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))
Deviations:
no
GLP compliance:
yes
Type of study:
other: Direct Peptide Reactivity Assay

Test material

Reference
Name:
Unnamed
Test material form:
liquid

In chemico test system

Details on study design:
The test item was tested by incubation with peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC.

Results and discussion

Positive control results:
The 100 mM stock solution of the positive control (cinnamic aldehyde) showed high reactivity towards the synthetic peptides. The mean depletion of both peptides was 64.92%.

In vitro / in chemico

Resultsopen allclose all
Parameter:
other: percentage depletion value of the cysteine
Run / experiment:
Mean depletion of the cysteine peptide
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of skin sensitisation
Parameter:
other: percentage deplation value of the lysine
Run / experiment:
Mean deplation of the lysine peptide
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
not determinable because of methodological limitations
Other effects / acceptance of results:
The samples containing test item and lysine peptide showed a distinct phase separation and furthermore a significant turbidity in both phases after the incubation time. Therefore, HPLC measurement of the samples was not possible and no results concerning the lysine peptide depletion of the test item are reported.

Applicant's summary and conclusion

Conclusions:
In this study under the given conditions the test item showed moderate reactivity towards the cysteine peptide. The test item can be classified as “non-sensitiser” in accordance with UN GHS “Category 1”.
Executive summary:

The in chemico direct peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine.

In the present study TEA Trioleate was dissolved in water.

The test item was tested by incubation with peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC.

The samples containing test item and lysine peptide showed a distinct phase separation and furthermore a significant turbidity in both phases after the incubation time. Therefore, HPLC measurement of the samples was not possible and no results concerning the lysine peptide depletion of the test item are reported.

After the 24 h ± 2 h incubation period but prior to the HPLC analysis the cysteine peptide samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for the test item samples. A slight precipitation was observed for standard 1 and the positive control samples. Since the acceptance criteria for the linearity of the standard curve as well as for the depletion range of the positive control were fulfilled, the observed precipitations were regarded as insignificant.

No co-elution of test item with the cysteine peptide peak was observed. Since the lysine peptide samples could not be measured, sensitising potential of the test item was predicted only from the peptide depletion of the cysteine peptide by comparing the peptide concentration of the test item treated samples to the corresponding reference control C (RC C).

The test item showed no reactivity towards the synthetic peptide. The mean depletion of the cysteine peptide was < 13.89% (0.00%). Based on the prediction model 2 the test item can be considered as non-sensitiser.

The 100 mM stock solution of the positive control (cinnamic aldehyde) showed high reactivity towards the synthetic peptides. The mean depletion of both peptides was 64.92%.