(2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate

Endpoint summary

Description of key information

The test stubstance was not a skin sensitiser.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS B.V., Inc. Postbus 6174 5960 AD Horst / The Netherlands
- Age at study initiation: 1st pre-test: 11 - 12 weeks 2nd pre-test: 10 - 11 weeks 3rd pre-test and main study: 9 - 10 weeks
- Weight at study initiation:
- Housing: group (Makrolon Type II (pre-test) / III (main study), with wire mesh top
- Diet (e.g. ad libitum): 2018C Teklad Global 18% protein rodent diet (certified), ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: at least 5 days prior

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 45 -65
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

1, 2.5 and 5% (w/w)

No. of animals per dose:

5

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

The mean values and standard deviations were calculated in the body weight tables, for the ear weights, the lymph node weights and lymph node cell count, and for the DPM values (group mean DPM ± standard deviation).
All calculations conducted on the DPM values, the ear weights, the lymph node weights and the lymph node cell count were performed with validated program R Script STABW-mitStat.Rnw.
Within the program a statistical analysis was conducted on the DPM values, the ear weights, the lymph node weights and the lymph node cell count to assess whether the difference was statistically significant between the test item groups and negative control group. Statistical significance was set at the five per cent level (p < 0.05). Additionally, the Dean-Dixon-Test and Grubb’s Test were used for identification of possible outliers. No outlier values were detected.

Remarks on result:

other: The EC3 value could not be calculated, since all S.I:`s are below the threshold value of 3

Interpretation of results:

GHS criteria not met

Conclusions:

The test item Isopropylidenglycerolmethacrylate (IPGMA) was not a skin sensitiser under the test conditions of this study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In this study the test item Isopropylidenglycerolmethacrylate (IPGMA) was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice. Test item solutions at different concentrations were prepared in the vehicle acetone/olive oil (4+1, v/v). For this purpose a local lymph node assay was performed using test item concentrations of 1, 2.5, and 5% (w/w). The highest concentration tested was the highest concentration that could be achieved whilst avoiding systemic toxicity and excessive local skin irritation (as determined by three pre-experiments). The animals neither showed any signs of systemic toxicity or local skin irritation nor mortality during the course of the study. A statistically significant but not biologically relevant increase in ear weights was observed in the high dose group in comparison to the vehicle control group (p<0.05). Furthermore, for BALB/c mice, a cut-off value of 1.1 for the ear weight index was reported for a positive response regarding ear skin irritation. None of the indices determined for the test item treated groups reached or exceeded this threshold. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices (S.I.) of 1.4, 1.1, and 1.3 were determined with the test item at concentrations of 1, 2.5, and 5% (w/w) in acetone/olive oil (4+1, v/v), respectively. An unusual dose response was observed. A statistical outlier was not detected in any group. A statistically significant or biologically relevant increase in DPM value, lymph node cell count and also in lymph node weight was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice was not reached or exceeded in the mid and high dose group. The test item Isopropylidenglycerolmethacrylate (IPGMA) was thus not a skin sensitiser under the test conditions of this study.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results, the test item is no subject to classification and labelling according to Regulation (EC) No 1272/2008 (CLP).