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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))
GLP compliance:
yes (incl. certificate)
Type of study:
not specified
Justification for non-LLNA method:
The study was performed in order to evaluate the reactivity of the test item N-(4-anilinophenyl)-4-methylbenzenesulfonamide towards cysteine (Cys-) and lysine (Lys-) containing peptides. A test item solution in acetonitrile was incubated 24 ± 2 h at 25 °C together with cysteine and lysine peptides, respectively, and the peptide concentration after the incubation was measured using HPLC-UV.

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

In vitro / in chemico

Resultsopen allclose all
Parameter:
other: Cys-peptide depletion
Value:
37.21
Parameter:
other: Lys-Peptide depletion
Value:
5.26
Parameter:
other: Mean peptide depletion
Value:
21.23

Any other information on results incl. tables

1.1     Evaluation of results

According to the test guideline, the reactivity is classified as “high”, “moderate”, “low” or “minimal” using the Cysteine 1:10/Lysine 1:50 prediction model shown in Table8.4–a.

 

Table8.4–a   Evaluation of results according to the Cysteine 1:10/Lysine 1:50 prediction model

Mean peptide depletion
[%]

Reactivity Class

DPRA Prediction

0 – ≤ 6.38

Minimal

Negative

> 6.38 – ≤ 22.62

Low

Positive

> 22.62 – ≤ 42.47

Moderate

> 42.47 - ≤ 100

High

 

The mean peptide depletion in the Lys-peptide and Cys-peptide assay was 21.23 %, therefore the test item was classified with:

 

DPRA Prediction: Positive

Reactivity class: Low

 

1.2     Proficiency

The ten proficiency chemicals listed in the guideline were tested using the analysis method described in chapter 6.2. Eight out of the ten chemicals showed depletion values consistent with the classification reported in the OECD guideline (LAUS in-house study).

1     Discussion

All acceptance criteria were fulfilled, therefore the test was considered valid. The DPRA prediction for the test itemN-(4-anilinophenyl)-4-methylbenzenesulfonamidewas positive with reactivity class low according to the Cysteine 1:10/Lysine 1:50 prediction model.

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
The DPRA predicition is “positive” with low reactivity according to the Cysteine 1:10/Lysine 1:50 prediction model.