2,2-di(tetrahydrofuryl)propane

Endpoint summary

Description of key information

Data for skin sensitization are available from a LLNA test performed according to OECD and EU guidelines as well as GLP principles. Based on the results of the test performed, Ditetrahydrofurylpropane is regarded as skin sensitizer. Based on a dose response, the EC3 value was calculated to be 87% . At 100% substance slight erythema was observed in one animal.

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

Study period:

11-30 July, 2007

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

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

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: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: approx. 11 weeks old
- Weight at study initiation: 22-28 g
- Housing: Individual housing in labeled Macrolon cages (MI type) containing sterilized sawdust as bedding material
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days before the start of treatment under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.1 - 23.7°C
- Humidity (%): 39 - 86%; Cleaning procedures in the room might have caused the temporary fluctuations above the optimal maximum level of 70% for relative humidity. Based on laboratory historical data, these fluctuations were considered not to have affected the study integrity.
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

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

Concentration:

Preliminary irritation study: 100%, 50%
Main study: 100%, 50%, 25%, 0%

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
- Irritation: slight erythema and no oedema at 100%, no erythema or oedema at 50%
- Lymph node proliferation response: not assessed

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymph node assay
- Criteria used to consider a positive response: DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group. If the results indicate a SI >= 3, the test substance may be regarded as a skin sensitiser, based on the test guideline and recommendations done by ICCVAM (NIH publication; No 99-4494, February 1999.)

TREATMENT PREPARATION AND ADMINISTRATION:
In the main study, three groups of five experimental animals were treated with test substance concentrations of 25%, 50% or 100% on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Acetone/Olive oil (4:1 v/v)).
Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised.
After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

Positive control substance(s):

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

Positive control results:

The SI values calculated for the substance concentrations 5, 10 and 25% were 1.3, 1.5 and 5.5 respectively. An EC3 value of 15.6% was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks of the recent years were 7.3, 10.3, 9.5 and 13.1%. Based on these results it was concluded that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity.

Parameter:

SI

Value:

1.6

Variability:

+/- 0.4

Test group / Remarks:

25%

Parameter:

SI

Value:

1.3

Variability:

+/- 0.3

Test group / Remarks:

50%

Parameter:

SI

Value:

3.6

Variability:

+/- 0.9

Test group / Remarks:

100%

Parameter:

EC3

Remarks:

value in %

Value:

87

Cellular proliferation data / Observations:

The disintegrations per minute (DPM) were 264 +/- 54, 424 +/- 75, 352 +/- 35 and 952 +/- 138 for respectively the control group and groups exposed to 25%, 50% and 100%.

One animal at 100% test substance concentration showed slight erythema on the ears. No erythema was noted in the other animals and no oedema was observed in any of the animals examined. The irritation of the ears as shown by one animal, was considered not to have a toxicologically significant effect on the activity of the nodes.

All nodes of the experimental and control groups were considered normal in size.

No macroscopic abnormalities of the surrounding area were noted.

Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. The slight body weight loss, noted in some animals, was considered not toxicologically significant.

No mortality occurred and no symptoms of systemic toxicity were observed in the animals of the main study.

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

An in vivo skin sensitistation study was performed according to OECD guideline 429 and GLP principles. The SI values calculated for the substance concentrations 25%, 50% and 100% were respectively 1.6, 1.3 and 3.6. These results indicate that the test substance could elicit an SI ≥ 3. The data showed a dose-response and an EC3 value of 87% test substance concentration was calculated. Based on these results, Ditetrahydrofurylpropane is regarded as skin sensitizer.

Executive summary:

In a skin sensitistation study performed according to OECD 429 test guidelines, three groups of five experimental animals were treated with ditetrahydrofurylpropane concentrations of 25%, 50% or 100% on three consecutive days,by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone. Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining lymph nodes were excised. Radioactivity measurements were performed and a Stimulation Index, SI, was subsequently calculated for each group. One animal at 100% test substance showed slight erythema on the ears. No other effects were seen. The SI values calculated for the substance concentrations 25, 50 and 100% were 1.6, 1.3 and 3.6, respectively. These results indicate that the test substance could elicit an SI >= 3. The data showed a dose-response and an EC3 value of 87% test substance concentration was calculated. Based on these results, Ditetrahydrofurylpropane is regarded as skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In a skin sensitistation study performed according to OEC429 test guidelines, three groups of five experimental animals were treated with ditetrahydrofurylpropane concentrations of 25%, 50% or 100% on three consecutive days,by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone. Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining lymph nodes were excised. Radioactivity measurements were performed and a Stimulation Index, SI, was subsequently calculated for each group. One animal at 100% test substance showed slight erythema on the ears. No other effects were seen. The SI values calculated for the substance concentrations 25, 50 and 100% were 1.6, 1.3 and 3.6, respectively. These results indicate that the test substance could elicit an SI >= 3. The data showed a dose-response and an EC3 value of 87% test substance concentration was calculated. Based on these results, Ditetrahydrofurylpropane would be regarded as skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The SI values calculated for the substance concentrations 25, 50 and 100% were 1.6, 1.3 and 3.6 respectively. These results indicate that the test substance could elicit an SI ≥ 3. The data showed a dose-response and an EC3 value of 87% test substance concentration was calculated. Based on these results, the substance is classified for skin sensitisation Category 1B, H317 according to the CLP Regulation (EC) 1272/2008.