Reaction mass of 2-dodecylhexadecyl methacrylate and 2-Tetradecyloctadecyl methacrylate

Endpoint summary

Description of key information

The skin sensitisation potential of Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) was assessed using the In Chemico Direct Peptide Reactivity Assay (DPRA) method according to OECD Test Guideline 442C. After a 24h incubation with both Cysteine and Lysine containing peptides, the percent peptide depletion was measured by High Performance Liquid Chromatography (HPLC).

For assessment of Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) the Cysteine peptide 1:10 prediction model was used. The final mean % peptide depletion observed using this model was 2.983%.

Therefore, Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) was classified as Negative with No or minimal reactivity as per the prediction model.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Details on the study design:

The DPRA is proposed to address the molecular initiating event of the skin sensitisation Adverse Outcome Pathway (AOP), namely protein reactivity, by quantifying the reactivity of test and reference items towards model synthetic peptides containing either Lysine or Cysteine. Cysteine and Lysine percent peptide depletion values are then used to categorise a substance in one of four classes of reactivity for supporting the discrimination between skin sensitisers and non-sensitisers.

Key result

Run / experiment:

other: final mean % peptide depletion

Parameter:

other: % peptide depletion

Value:

2.983

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: None reported

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: YES
- Acceptance criteria met for positive control: YES
- Acceptance criteria met for variability between replicate measurements: YES

Prior to the main test, the test item was assessed for solubility and was found to be soluble in Isopropanol at 100mM.

Name	Test Item ID	% Cysteine Peptide Depletion	% Lysine Peptide Depletion	Mean % Peptide Depletion (Cys + Lys)	DPRA Prediction based on Cysteine 1 :10 prediction model	DPRA Reactivity Class
Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0)	TA1	2.983	Acceptance criteria not met, not included in the analysis	Not applicable	Negative	No or minimal reactivity

Interpretation of results:

other: Negative with No or minimal reactivity

Conclusions:

Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) was classified as Negative with No or minimal reactivity as per the prediction model for skin sensitisation.

Executive summary:

The skin sensitisation potential of Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) was assessed using the In Chemico Direct Peptide Reactivity Assay (DPRA) method according to OECD Test Guideline 442C. After a 24h incubation with both Cysteine and Lysine containing peptides, the percent peptide depletion was measured by High Performance Liquid Chromatography (HPLC).

For assessment of Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) the Cysteine peptide 1:10 prediction model was used. The final mean % peptide depletion observed using this model was 2.983%.

Therefore, Reaction mass of 2-Propenoic acid, 2-methyl-, 2-dodecylhexadecyl ester and 2-Propenoic acid, 2-methyl-, 2-tetradecyloctadecyl ester (EC 946-978-0) was classified as Negative with No or minimal reactivity as per the prediction model.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In accordance with Annex VII of REACH, a batch of three in vitro skin sensitisation studies shall be conducted. However, it was not technically feasible to perform an OECD 442D due to an insufficient solubility in the exposure medium and an OECD 442E due to the high Log Kow (> 6.5) of the registered substance.

Justification for classification or non-classification

An OECD 442C conducted on the registered substance returned a negative result, indicating no or minimal reactivity. It was not technically feasible to conduct OECD 442D and OECD 442E due to the physicochemical properties of the substance. Based on the available information, it is concluded that the substance does not meet the criteria for classification according to Regulation (EC) 1272/2008.