2-propenoic acid, 2-methyl-, 4-benzoylphenyl ester

Endpoint summary

Description of key information

A Local Lymphnode Assay (LLNA) acc. OECD 429 was performed In order to study a possible contact allergenic potential of Benzophenone methacrylate. Three groups each of four female mice were treated daily with the test item at concentrations of 5, 10, and 25% (w/v) in acetone:olive oil (4+1) by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (acetone:olive oil (4+1)) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (³H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of³H-methyl thymidine measured in ab-scintillation counter.

All treated animals survived the scheduled study period and no signs of toxicity were observed.

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of³HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.66, 2.77, and 1.80 were determined with the test item at concentrations of 5, 10, and 25% in acetone:olive oil (4+1).

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:

03.11.2009 to 17.11.2009

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)

Specific details on test material used for the study:

4-(Methacryloyloxy) bezophenone 97.3 %
Benzophenone acetate: 1.95 %

Species:

mouse

Strain:

CBA/Ca

Remarks:

Mice, CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

Test system: Mice, CBA/CaOlaHsd
Rationale: Recognised as the recommended test system
Source Harlan Laboratories B.V., Postbus 6174,5960 AD Horst / The Netherlands
Number of animals for the pre-test: 2 females
Number of animals for the main study: 16 females
Number of animals per group: 4 females (nulliparous and non-pregnant)
Number of test groups: 3
Number of control (vehicle) groups: 1
Age: 8 - 12 weeks (beginning of treatment)

Identification:
Single caging. The animals were distributed into the test groups at random and identified by cage number.
Acclimatisation:
At least 5 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness were used for the study.

Husbandry:
The animals were kept conventionally. The experiment was conducted under standard laboratory conditions.
Housing: single
Cage Type: Makrolon Type II, with wire mesh top
Bedding: granulated soft wood bedding
Feed: pelleted standard diet, ad libitum
Water: tap water, ad libitum

Environment:
temperature 22 + 2°C
relative humidity 45-65%
artificial light 6.00 a.m. - 6.00 p.m.

Vehicle:

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

Concentration:

0%, 5%, 10%, 25%

No. of animals per dose:

4

Details on study design:

Vehicle and Dose Selection (Pre test)
A solubility experiment was performed according to the recommendations given by OECD 429. The highest test item concentration, which can be technically used was a 25 % solution in acetone:olive oil (4+1).
To determine the highest non-irritant test concentration, a pre-test was performed in two animals. Two mice were treated with concentrations of 10 and 25% each on three consecutive days.
In the pre-test clinical signs were recorded within 1 hour and 24 ± 4 hours after each application as well as on day 7. At the tested concentrations the animals did not show any signs of irritation or systemic toxicity.
The test item in the main study was assayed at 5, 10, and 25%. The top dose is the highest technically achievable concentration whilst avoiding systemic toxicity and excessive local irritation. No severe irritant effects were tolerated choosing the test concentrations.

Main testThree groups each of four female mice were treated daily with the test item at concentrations of 5, 10, and 25% (w/v) in acetone:olive oil (4+1) by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (acetone:olive oil (4+1)) only. Clinical signs were recorded within 1 hour each application, and 24 ± 4 hours after the first and second application as well as on the day of preparation. Especially the treatment sites were observed carefully. Five days after the first topical application the mice were injected intravenously into a tail vein with radiolabelled thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight.
The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a scintillation counter.

Positive control substance(s):

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

Key result

Parameter:

SI

Value:

1.66

Variability:

5% test item in acetone:olive oil (4+1)

Test group / Remarks:

Group 2

Key result

Parameter:

SI

Value:

2.77

Variability:

10% test item in acetone:olive oil (4+1)

Test group / Remarks:

Group 3

Key result

Parameter:

SI

Value:

1.8

Variability:

25% test item in acetone:olive oil (4+1)

Test group / Remarks:

Group 4

Interpretation of results:

GHS criteria not met

Conclusions:

In this study Stimulation Indices of 1.66, 2.77, and 1.80 were determined with the test item at concentrations of 5, 10, and 25% in acetone:olive oil (4+1). The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.
The test item Benzophenone methacrylate was not a skin sensitiser under the described conditions.

Executive summary:

A Local Lymphnode Assay (LLNA) acc. OECD 429 was performed In order to study a possible contact allergenic potential of Benzophenone methacrylate. Three groups each of four female mice were treated daily with the test item at concentrations of 5, 10, and 25% (w/v) in acetone:olive oil (4+1) by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (acetone:olive oil (4+1)) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (³H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of³H-methyl thymidine measured in ab-scintillation counter.

All treated animals survived the scheduled study period and no signs of toxicity were observed.

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of³HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.66, 2.77, and 1.80 were determined with the test item at concentrations of 5, 10, and 25% in acetone:olive oil (4+1). The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.

In conclusion the test item Benzophenone methacrylate is not a skin sensitiser and has not to be classified..

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of³HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 1.66, 2.77, and 1.80 were determined with the test item at concentrations of 5, 10, and 25% in acetone:olive oil (4+1). The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.

In conclusion the test item Benzophenone methacrylate is not a skin sensitiser and has not to be classified..