1,10-dichlorodecane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))

Version / remarks:

Deviations: Concerning:
Study Director, study plan p. 2, 6
Study Plan:Study Director: Dr. Claudia Steinert
Report: Study Director:Kristin Rödig
Reason:Project handover
•Concerning:Introduction, study plan, p. 09
Study Plan:The assessment of skin sensitisation typically involves the use of laboratory animals. Classical methods comprise the Magnusson Kligman Guinea Pig Maximisation Test, the Buehler Test (test guideline (TG) 406) [7] as well as the Local Lymph Node Assay, in its radioactive and non-radioactive form (TG 429, TG 422A/B) [8], [9], [10].
Report:The assessment of skin sensitisation typically involves the use of laboratory animals. Classical methods comprise the Magnusson Kligman Guinea Pig Maximisation Test, the Buehler Test (test guideline (TG) 406) [7] as well as the Local Lymph Node Assay, in its radioactive and non-radioactive form (TG 429, TG 442A/B) [8], [9], [10].
Reason:Typing error.

Deviations:

yes

Remarks:

These deviations did not influence the quality or integrity of the present study.

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Test material

Test material information

Constituent 1

Reference substance name:

1,10-dichlorodecane

EC Number:

218-489-6

EC Name:

1,10-dichlorodecane

Cas Number:

2162-98-3

Molecular formula:

C10H20Cl2

IUPAC Name:

1,10-dichlorodecane

Test material form:

liquid

In chemico test system

Details on the study design:

This test method is able to detect chemicals that cause skin sensitisation and may be used on its own to classify a chemical into UN GHS “Category 1”. Data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of an integrated approach such as IATA, combining them with other complementary information e.g., derived from in vitro assays addressing other key events of the AOP.

Results and discussion

Positive control results:

Cinnamic aldehyde ((2E)-3-phenylprop-2-enal) was solved in acetonitrile and was used as positive control. A stock concentration of 100 mM was prepared and was included in every assay run for both peptides. Mean Peptide Depletion [%] Reactivity Category Prediction Mean Peptide Depletion [%] Reactivity Category Prediction

69.10 High Reactivity sensitiser 75.07 Moderate Reactivity sensitiser

In vitro / in chemico

Results

Results 1

Key result

Parameter:

other: The mean depletion of the cysteine peptide

Value:

0

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

valid

Results 2

Key result

Run / experiment:

mean

Parameter:

other: Mean Peptide Depletion Lysine [%]

Value:

15.19

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

valid

Other effects / acceptance of results:

Prediction Model 1 Prediction Model 2
(Cysteine Peptide and Lysine Peptide / Ratio: 1:10 and 1:50) (Cysteine Peptide / Test Item Ratio: 1:10)

Mean Peptide Depletion [%] Reactivity Category Prediction Mean Peptide Depletion [%] Reactivity Category Prediction
- - - 0.00 Minimal Reactivity no sensitiser

Any other information on results incl. tables

The in chemico direct peptide reactivity assay (DPRA) enables detection of the sensitising potential of a test item by addressing the molecular initiating event of the adverse outcome pathway (AOP), namely protein reactivity, by quantifying the reactivity of test chemicals towards synthetic peptides containing either lysine or cysteine. The percentage depletion value of the cysteine and lysine peptide is used to categorize a substance in one of four reactivity classes to support discrimination between skin sensitisers and non-sensitisers. In the present study 1,10-Dichlorodecane was dissolved in acetonitrile, based on the results of the pre-experiments. Based on a molecular weight of 211.18 g/mol a 100 mM stock solution was prepared. The test item solutions were tested by incubating the samples with the peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC. For the 100 mM solution of the test item no turbidity or precipitation was observed when diluted with the cysteine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples. For the 100 mM solution of the test item no turbidity or precipitation was observed when diluted with the lysine peptide solution. After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. Phase separation was observed for the samples of the positive control including the co-elution control). Turbidity was also observed for the samples of the test item. Samples were not centrifuged prior to the HPLC analysis. Since the acceptance criteria for the depletion range of the positive control were fulfilled, the observed phase separation was regarded as insignificant. Co-elution of the test item with the lysine peptide peak was observed. Therefore, the given peak areas and corresponding lysine peptide values can only be considered as an estimation of the peptide depletion and cannot be used for evaluation. Sensitising potential of the test item was predicted from the mean 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_acetonitrile). The 100 mM stock solution of the test item showed minimal 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 69.10%. The controls confirmed the validity of the study for both, the cysteine and lysine run.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this study under the given conditions the test item showed minimal reactivity towards both peptides. The test item might be considered as “non-sensitiser”.
The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.

Executive summary:

The in chemicodirect 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 1,10-Dichlorodecane was dissolved in acetonitrile, based on the results of the pre-experiments. Based on a molecular weight of 211.18 g/mol a 100 mM stock solution was prepared. The test item solutions were tested by incubating the samples with the peptides containing either cysteine or lysine for 24 ± 2 h at 25 ± 2.5 °C. Subsequently samples were analysed by HPLC.

For the 100 mM solution of the test item no turbidity or precipitation was observed when diluted with the cysteine peptide solution. After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. No precipitation, turbidity or phase separation was observed for any of the samples.

For the 100 mM solution of the test item no turbidity or precipitation was observed when diluted with the lysine peptide solution.After the 24 h±2 h incubation period but prior to the HPLC analysis samples were inspected for precipitation, turbidity or phase separation. Phase separation was observed for the samples of the positive control including the co-elution control). Turbidity was also observed for the samples of the test item. Samples were not centrifuged prior to the HPLC analysis.

Since the acceptance criteria for the depletion range of the positive control were fulfilled, the observed phase separation was regarded as insignificant.

Co-elution of the test item with the lysine peptide peak was observed. Therefore, the given peak areas and corresponding lysine peptide values can only be considered as an estimation of the peptide depletion and cannot be used for evaluation.

Sensitising potential of the test item was predicted from the mean 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_acetonitrile).

The 100 mM stock solution of the test item showed minimal 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 69.10%.