2-Propenoic acid, 2-methyl-, hydroxybutyl ester

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 Feb to 1 march, 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Done by OECD and GLP standards

Data source

Reference

Reference Type:

other: Unnamed report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Test material form:

liquid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

At the start of the study the mice were in the weight range of 15 to 23 grams and were8 to 12 weeks old. Animlas were acclimatised for 5 days prior to the study. Free access to mains drinking water and food was allowed through out the study. The temperature and relative humidity were set to achieve limits of 19 to 25 C and 30 to 70% respectively. The lighting was controlled by a time switch to give 12 hours continuous light and 12 hours of darkness.

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

test material at concentrations of 25% & 50% in acetone/olive oil and 100% w/w.

No. of animals per dose:

Three groups of four animals each were treated at each concentration group and a further group of five animals were treated as a control group with acetone/olive oil alone.

Details on study design:

The mice were treated by daily application of 25 μl of the appropriate concentration of the test material to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3) by using a micropipette whose tip is used to spread the formulation over the dorsal surface of each ear. On Day 6 all mice were injected with 250 ul of a phophate buffered saline solution containing 3H-methyl thymidine (3HTdR ) to the tail vein giving a total of 20 uCi to each mouse. All animals were observed twice daily on Day 1, 2 and 3 and once daily on days 4 ,5, and 6. Any signs of toxicity or ill health were noted. Body weights of each mouse were recorded before dosing and before termination. Five hours after administration of 3HTdR all mice were killed by carbon dioxide asphyxiation and their auricular lymph nodes were excised and a 1 ml of phosphate buffered saline was added to each set of lymph nodes. Preparation of a single cell suspension was completed for the lymph nodes cells for each individual animal following standard procedures. Determination of the 3HTdR incorporation was completed by measuring radioactive disintegration for each animal's lymph node cells by using a beta-scintillation counter.

Positive control substance(s):

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

Results and discussion

Positive control results:

Considered positve for skin sentization.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

Concentration of test material in the vehicle at 25 % resulted in a stimulation index (SI) of 1.16 which is a negative result.Concentration of test material in the vehicle at 50 % resulted in a stimulation index (SI) of 1.83 which is a negative result.Concentration of test material at 100% resulted in a stimulation index (SI) of 0.61 which is a negative result. A stimulation index of less than 3 was recorded for the three concentrations of the test material.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Concentration of test material in the vehicle at 25 % resulted in a mean disintegration of 122254.42 dpm which is a negative result.Concentration of test material in the vehicle at 50 % resulted in a mean disintegration of 19373.89 dpm which is a negative result. Concentration of test material at 100 % resulted in a mean disintegration of 6496.02 dpm which is a negative result. The results of the statistical analysis of the data indicated there was no significant difference between the control group and the test groups.

Results 3

Parameter:

SI

Remarks:

(SI) of 1.16 which is a negative result.Concentration of test material in the vehicle at 50 % resulted in a stimulation index

Value:

ca. 1.16

Test group / Remarks:

25% concentration

Remarks on result:

other:

Remarks:

Concentration of test material in the vehicle at 25 % resulted in a stimulation index (SI) of 1.16 which is a negative result.

Results 4

Parameter:

SI

Remarks:

(SI) of 1.83 which is a negative result.Concentration of test material at 100% resulted in a stimulation index

Value:

ca. 1.83

Test group / Remarks:

50% concentration

Remarks on result:

other:

Remarks:

Concentration of test material in the vehicle at 50 % resulted in a stimulation index (SI) of 1.83 which is a negative result.

Results 5

Parameter:

SI

Value:

ca. 0.61

Test group / Remarks:

100% concentration

Remarks on result:

other:

Remarks:

Concentration of test material at 100% resulted in a stimulation index (SI) of 0.61 which is a negative result. A stimulation index of less than 3 was recorded for the three concentrations of the test material.

Any other information on results incl. tables

There were no deaths. No signs of systemic toxicity were noted in the test or control animals

during the test. Body weight chnages of the test animals between day 1 to day 6 were comparable to body weight changes of the control animals over the same period.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material was considered to be non-sensitising under conditions of the test.