2,5-dimethylhexane-2,5-diol

Skin sensitisation

Administrative data

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:

other: OECD guideline study conducted according to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

2,5-dimethylhexane-2,5-diol

EC Number:

203-731-5

EC Name:

2,5-dimethylhexane-2,5-diol

Cas Number:

110-03-2

Molecular formula:

C8H18O2

IUPAC Name:

2,5-dimethylhexane-2,5-diol

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

5, 10, and 25% (w/w)

No. of animals per dose:

5

Details on study design:

The study was conducted according to OECD guideline 429.

Statistics:

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 test item groups and negative control group. For all statistical calculations SigmaStat for Windows (Version 2.0) was used. A One-Way-Analysis-of-Variance was used as statistical method. In case of significant results of the One-Way-ANOVA, multiple comparisons were performed with the Dunnett test. Statistical significance was set at the five per cent level (p < 0.05). The Dean-Dixon-Test and Grubb’s test were used for identification of possible outliers (performed with Microsoft Excel 2003).

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: control group: 1.00 5%: 0.82 10%: 1.05 25%: 0.78

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: control group: 1291.7 5%: 1059.3 10%: 1360.9 25%: 1001.3

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item 2,5-Dimethyl-2,5-hexanediol was not a skin sensitiser in the Local Lymph Node Assay.

Executive summary:

In this study the test item 2,5-Dimethyl-2,5-hexanediol was assessed for its skin sensitising potential using the Local Lymph Node Assay (LLNA) in mice. Test item solution at different concentrations was prepared in the vehicle dimethylformamide. For this purpose a local lymph node assay was performed using test item concentrations of 5, 10, and 25% (w/w). The highest concentration tested was the highest concentration that could be technically used and applied whilst avoiding systemic toxicity and excessive local skin irritation (as determined by a pre-experiment).

The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of mortality were observed. A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. In this study Stimulation Indices (S.I.) of 0.82, 1.05, and 0.78 were determined with the test item at concentrations of 5, 10, and 25% (w/w) in dimethylformamide, respectively. An outlier was identified in the low dose group. However, an exclusion of the outlier did not change the overall test result and, therefore, the value in question was not excluded from calculation.

A statistically significant or biologically relevant increase in DPM value and also in lymph node weight and cell count was not observed in any of the tested dose groups in comparison to the vehicle control group.