2-Propenoic acid, 2-methyl-, 7-oxabicyclo[4.1.0]hept-3-ylmethyl ester

Endpoint summary

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:

April - May 2014

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
- Species/strain: healthy CBA/CaOlaHsD mice
- Source: Harlan Laboratories
- Sex: female (nulliparous and non-pregnant)
- Age at the beginning of the study: 9-10 weeks
- Number of animals: 5 mice / group, 7 mice / prescreen test
The animals were derived from a controlled full-barrier maintained breeding system (SPF). According to Art. 9.2, No. 7 of the German Act on Animal Welfare the animals are bred for experimental purposes.
The animals were randomly selected. Identification was ensured by cage number and individual marking (tail).

HOUSING AND FEEDING CONDITIONS
- Full barrier in an air-conditioned room
- Temperature: 22 ± 3 °C
- Relative humidity: 55 ± 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: at least 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice (prescreen test and main study: lot no. 1526)
- Free access to tap water, sulphur acidified to a pH value of approx. 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- The animals were kept in groups of 5 animals in IVC cages, type II L, polysulphone cages on Altromin saw fibre bedding (prescreen test: lot no. 131113, main study: lot no. 290114)
- Certificates of food, water and bedding are filed at the test institute
- Adequate acclimatisation period (at least five days) under laboratory conditions

Vehicle:

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

Concentration:

12.5, 25 and 50%

No. of animals per dose:

5

Details on study design:

The LLNA has been developed as an alternative method for the identification of skin sensitising test items and measures the proliferation of lymphocytes isolated from lymph nodes (auricular lymph nodes) draining the site of exposure (dorsal aspect of the ears) in mice.
Lymphocyte proliferation is measured by determining the incorporation of 3H-methyl thymidine (TRK 300, 20 Ci/mmol, Lot 201310E, diluted to a working concentration of 80 µCi/mL).

Positive control substance(s):

other: Reliability check with p-phenylenediamine (CAS 106-50-3, > 94%) in May 2014 (BSL Project ID 134702 Z)

Positive control results:

RELIABILITY CHECK (May 2014, mean values):

Negative Control (vehicle):
- CPM 827.4
- DPM 2155.8
- SI 1.0

Positive Control (p-phenylenediamine):
- CPM 5616.0
- DPM 14577.8
- SI 6.8

Parameter:

SI

Remarks:

mean

Value:

2.8

Test group / Remarks:

12.5% test item

Remarks on result:

other: no signs of systemic toxicity nor excessive irritation

Parameter:

SI

Remarks:

mean

Value:

4.6

Test group / Remarks:

25% test item

Remarks on result:

other: further observation: sticky fur (day 3-5)

Key result

Parameter:

EC3

Value:

13.89

Test group / Remarks:

derived by linear interpolation

PRESCREEN TEST

No signs of excessive irritation indicated by an erythema score ≥ 3 and/or ear swelling of ≥ 25% were detected in any animal.

The animals treated with the undiluted test item as well as the animals treated with the test item at a concentration of 50% in AOO showed signs of systemic toxicity (weight loss > 10%).Therefore, animal no. 1, 2 and 3 were sacrificed for ethical reasons on day 3. All other clinical findings (sticky fur, found in animal no. 1 to 5) were considered not to be signs of systemic toxicity or signs of excessive irritation.

No signs of irritation were detected in the animals treated with the negative control.

All surviving animals showed the expected weight development, which includes a weight loss of up to 2 g (ca. 5-10%) throughout the duration of the prescreen test.

Group	Animal No.	Weight change [g]	Weight change [%]	Systemic Effects	Local Effects
100%	1*	-3	-14.29	weight loss	sticky fur
100%	2*	-3	-15.00	weight loss	sticky fur
50%	3*	-3	-14.29	weight loss	sticky fur
50%	4	1	4.76	-	sticky fur
25%	5	-1	-4.55	-	sticky fur
25%	6	1	4.55	-	-
Control	7	0	0.00	-	-

* euthanised on day 3

MAIN STUDY

One of the two tested concentrations exceeded the stimulation index of 3.

The stimulation index at a concentrationof        12.5% was     2.8

The stimulation index at a concentrationof        25%    was     4.6

The stimulation index at a concentration of 50% could not be measured.

No signs of excessive irritation indicated by an erythema score ≥ 3 and/or ear swelling of ≥ 25%were detected in any animal.

The animals treated with the test item at a concentration of 50% in AOO showed signs of systemic toxicity (weight loss > 10%) Therefore, the animals of the 50% test group were sacrificed for ethical reasons on day 3.

In all animals treated with the test item at a concentration of 50% in AOO and a concentration of 25% in AOO sticky fur was observed from day 2 (50% concentration) or from day 3 (25% concentration) until day 5.

Neither signs of systemic toxicity nor signs of excessive irritation at any application site could be detected in any animal treated with the test item at a concentration of 12.5% in AOO.

A weight loss of 3 g was observed in 4 out 5 animals treated with the test item at the concentration of 50 % on day 3. Therefore the animals were euthanized for ethical reason. The remaining animals showed the expected weight development, which includes a weight loss of up to 2 g (ca. 5-10%) throughout the study.

Group	Animal No.	Weight change [g]	Weight change [%]	Systemic Effects	Local Effects
12.5%	1	1	4.55	no findings	no findings
	2	0	0.00
	3	1	4.17
	4	1	4.76
	5	1	4.76
25%	6	-2	-8.70	no findings	wet fur (neck) day 3 -5
	7	-1	-4.55
	8	0	0.00
	9	1	4.35
	10	0	0.00
50%	11*	-3	-12.50	weight loss > 10% on day 3*	wet fur (neck) day 2 -3*
	12*	-3	-13.64
	13*	-3	-15.00
	14*	-2	-8.70
	15*	-3	-13.04
Control	16	0	0.00	no findings	no findings
	17	0	0.00
	18	1	4.55
	19	-1	-5.26
	20	0	0.00

* euthanised on day 3

The means of the ear thickness per group showed no relevant difference compared to the negative control:

Mean ear thickness	day 1	day 3	day 6
12.5% test group	0.18 mm	0.18 mm	0.18 mm
25% test group	0.18 mm	0.19 mm	0.19 mm
50% test group	0.18 mm	0.18 mm	-
negative control group	0.18 mm	0.18 mm	0.18 mm

Interpretation of results:

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

Conclusions:

The EC3 value (derived by linear interpolation) was calculated to be at a test item concentration of 13.89%.
The measurement of the ear thickness did not revealany relevant increase of the ear thickness in any dosage group.
Consequently, according to OECD 429, solutions or preparations containing more than 13.89% 3,4-Epoxycyclohexylmethyl methacrylate are expected to have a stimulation index of >3, and are therefore considered to be dermal sensitisers.
According to Commission Regulation (EU) No 286/2011 as well as GHS (Globally Harmonized Classification System) the test item 3,4-Epoxycyclohexylmethyl methacrylate has obligatory labelling requirement for skin sensitisation and is classified into Category 1B.

Executive summary:

SUMMARY

On the basis of the test results given below and in conformity with the criteria given in Commission Regulation (EU) No 286/2011 the substance should be:

- classified into sub-category 1B

On the basis of the test results given below and in conformity with the criteria given in GHS (Globally Harmonized Classification System) the substance should be:

- classified into sub-category 1B

Based on the results of the prescreen test the test item was assessed for sensitising properties at concentrations of 12.5%, 25% and 50% (v/v), each diluted with AOO 4:1 (v/v). Animals which showed adverse clinical findings or were euthanized for ethical reasons were excluded from the calculation.

Species/strain: Mice, CBA/CaOlaHsd

Number of animals: 20/main test

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

One of the two tested concentrations exceeded the stimulation index of 3.

The stimulation index at a concentration of        12.5% was     2.8

The stimulation index at a concentration of        25%    was     4.6

The stimulation index at a concentration of 50% could not be measured as the animals treated with a 50% concentration were euthanized for ethical reasons on day 3.

 

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Migrated from Short description of key information:
sensitising | mouse (female) | OECD 429 |

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

3,4-Epoxycyclohexylmethyl methacrylate was tested for skin sensitization in a GLP-compliant study according to OECD TG 429 (LLNA, Klimisch 1). Under the conditions of the study, an EC3 value of 13.89% was derived. On the basis of the outcome of this assay, 3,4-epoxycyclohexylmethyl methacrylate has to be classified as skin sensitizer.

Justification for classification or non-classification

The available data suggest a skin sensitization potential. Therefore, 3,4-epoxycyclohexylmethyl methacrylate has to be classified accordingly with "Skin Sens. 1B, H317" under the CLP regulation (Regulation (EC) 1272/2008).