A mixture of: propan-2-one-O,O'-(methoxymethylsilandiyl)dioxime; propan-2-one-O-(dimethoxymethylsilyl)oxime; propan-2-one-O,O',O''-(methylsilantriyl)trioxime

Endpoint summary

Description of key information

Key study: OECD Guideline 429 and GLP. The test substance Wasox-MMAC2 was regarded as a non sensitizer, since the SIs of all examined test substance concentrations were clearly smaller than 3.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 12-19, 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

According to OECD Guideline 429, with GLP.

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

GLP compliance:

yes

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: Harlan Winkelman
- Age at study initiation: 8 weeks
- Weight at study initiation: 17.0-19.9 g
- Housing: single caging. Makrolon cages type II
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.8 ºC (average)
- Humidity (%): 48.2% (average)
- Photoperiod (hrs dark / hrs light): only artificial light from 6.00 a.m. to 6.00 p. m.

Vehicle:

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

Concentration:

High dose: 100% test substance (as it is).
Mid dose: 50% (v/v) solution of the test substance in acetone:olive oil.
Low dose: 25% (v/v) solution of the test substance in acetone:olive oil.

No. of animals per dose:

five female mice/dose level.

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: Solubility testing showed that the test substance solves for at least 50% (v/v) in vehicle AOO.
- Irritation: about 24 hours after the last administration of the test substance as it is (100%) little increase in ear thickness was observed.

TREATMENT PREPARATION AND ADMINISTRATION:
Administration was performed epicutaneously to the dorsal surface of both ears, once a day on three consecutive days. The volume administered was 25 µL per ear.

Positive control substance(s):

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

Positive control results:

Application of 25% HCA in AOO resulted in a positive control result of 42767 dpm (desintegrations per minute) and a SI (Stimulation Index) of 10.2. This result proves the sensitivity of the strain of animals used and the reliability of the experimental technique.

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

Negative control

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

Low dose

Key result

Parameter:

SI

Value:

0.8

Test group / Remarks:

Mid dose

Key result

Parameter:

SI

Value:

0.7

Test group / Remarks:

High dose

Key result

Parameter:

SI

Value:

10.2

Test group / Remarks:

Positive control

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Negative Control: 4197dpm Low Dose: 4217 dpm Mid Dose: 3536 dpm High Dose: 2919 dpm Positive Control: 42767 dpm

Mortality:

All animals survived till the end of the study.

General observations:

One animal of group C had reduced motoric activities on Day 6. In all other animals no abnormal behaviour or clinical signs were detected during the experiment.

Skin reactions:

No local irritations were observed at the application sites of all animals of all test substance groups and both control groups throughout the whole study.

Body masses:

Body masses and body mass gains of all animals were in the range to be expected from animals of the same strain, sex and age.

Body weight loss was noted in 1/5 animals in group B and C.

Body mass of the animals on Days 1 and 6. Individual body masses (b.m.) and body mass gains in g of all animals. Means, standard deviations (SD) and number of animals per group (n).

Group K (negative control)				Group A (low dose)				Group B (mid dose)				Group C (high dose)				Group P (positive control)
Animal no,	b.m. on day		b.m. gain	Animal no,	b.m. on Day		b.m. gain	Animal no,	b.m. on Day		b.m. gain	Animal no,	b.m. on Day		b.m. gain	Animal no,	b.m, on Day		b.m. gain
	1	6			1	6			1	6			1	6			1	6
1	18.9	21,1	2.2	6	17.8	19.2	1.4	11	19.8	19.4	-0.4	16	19.9	20.9	1.0	21	18.3	19.0	0.7
2	18.7	20.3	1.6	7	17.3	19.3	2.0	12	17.8	20.0	2.2	17	18.6	20.0	1.4	22	19.9	21.3	1.4
3	19.4	20.0	0.6	8	18.8	21.7	2.9	13	17.8	20.8	3.0	18	17.6	16.9	-0.7	23	17.3	18.9	1.6
4	17.8	17.8	0.0	9	18.9	20.1	1.2	14	18.1	20.0	1.9	19	17.3	20.7	3.4	24	18.0	18.9	0.9
5	19.7	21.3	1.6	10	17.0	20.9	3.9	15	18.7	19.5	0.8	20	18.2	19.6	1.4	25	19.3	19.8	0.5
mean	18.9	20.1	1.2	mean	18.0	20.2	2.3	mean	18.4	19.9	1.5	mean	18.3	19.6	1.3	mean	18.6	19.6	1.0
SD	0.7	1.4	0.9	SD	0.9	1.1	1.1	SD	0.8	0.6	1.3	SD	1.0	1.6	1.5	SD	1.0	1.0	0.5
n	5	5	5	n	5	5	5	n	5	5	5	n	5	5	5	n	5	5	5

Simulation index:

Evidence of sensitisation of each challenge concentration:

Results are presented as test/control ratio (Stimulation index), calculated as dpm test group/dpm negative control group, (dpm - disintegrations per minute, corrected by the subtraction of the background).

	Dpm	SI
Group K (negative control)	4197	1
Group A (Iow dose)	4217	1.0
Group B (mid dose)	3536	0.8
Group C (high dose)	2919	0.7
Group P (positive control)	42767	10.2

The Sis of the test substance groups were between 0.7 and 1.

Application of 25% HCA in AOO resulted in an SI of 10.2. This result proves the sensitivity of the strain of animals used and the reliability of the experimental technique.

Interpretation of results:

other: Not classified (CLP Regulation EC no. 1272/2008)

Conclusions:

The test substance Wasox-MMAC2 is regarded as a non sensitizer in the "Skin Sensitisation: Local Lymph Node Assay", since the SIs of all examined test substance concentrations were clearly smaller than 3.

Executive summary:

The "Skin Sensitisation: Local Lymph Node Assay" for the test substance Wasox-MMAC2 was performed in five groups of 5 female CBA mice (According to OECD Guideline 429). The doses tested were 100% of test material (as it is); 50% (v/v) and 25 % (v/v). The vehicle used was acetone:oil (4:1, v/v) (AOO). A positive control (25% solution of hexyl cinnamic aldehyde in AOO) and a negative control (AOO) were included on the test. Both control substances were administrated under identical conditions as the test substance. The Administration was performed epicutaneously to the dorsal surface of both ears, once a day on three consecutive days. The volume administrated was 25 µl per ear. 5 days after the first topical administration, each animal received 20 µlCi3HTdR by intravenous administration. Approximately 5 hour after 3HTdR injection all animals were sacrificed and the 3HTdR incorporation determinate. The application sites were visually checked for local irritations at least once a day. Body weight was recorded on days 1 and 6 after the administration. The test substance is regarded as a not sensitising, since the SIs of all examined test substance concentrations were clearly smaller than 3, and therefore the substance was determined to be not sensitising.

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study are available

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
An in vitro study does not need to be conducted since adequate data from an in vivo skin sensitisation study are available.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Key study: The Skin Sensitisation: Local Lymph Node Assay for the test substance Wasox-MMAC2 was performed in five groups of 5 female CBA mice according to OECD Guideline 429 and GLP. The test substance was regarded as a non sensitizer, since the SIs of all examined test substance concentrations were clearly smaller than 3.

Justification for selection of skin sensitisation endpoint:

Only one study available.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available information on skin sensitization, the substance is not classified according to CLP Regulation (EC) no. 1272/2008.