BAP

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 February 2018 to 05 September 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), Testing Guidelines for Toxicology Studies, 12 NouSan No. 8147, 24 November 2000

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

dimethyl hydrogen phosphorate, compound with 4-tetrapropyleneaniline {SIDSep} Phosphoric acid, monomethyl ester, compd. with 4-tetrapropylenebenzenamine (1:1)

Molecular formula:

N/A

IUPAC Name:

dimethyl hydrogen phosphorate, compound with 4-tetrapropyleneaniline {SIDSep} Phosphoric acid, monomethyl ester, compd. with 4-tetrapropylenebenzenamine (1:1)

Test material form:

liquid: viscous

Details on test material:

Physical Appearance: dark amber, viscous paste

Specific details on test material used for the study:

- Purity:99.5% (UVCB)
- Description: Brown colored paste

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/Ca (CBA/CaOlaHsd)

Sex:

female

Details on test animals and environmental conditions:

The animals were housed in suspended solid floor polypropylene cages with stainless steel mesh lids and furnished with softwood flakes bedding (Datesand Ltd., Cheshire, UK).

The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70%, respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

Test material at concentrations of 50, 25 or 10 (%w/w) in acetone/olive oil 4:1

No. of animals per dose:

5

Positive control substance(s):

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

Statistics:

Data was processed to give group mean values for disintegrations per minute and standard deviations where appropriate.

Results and discussion

Positive control results:

α-Hexylcinnamaldehyde, tech., 85% was considered to be a sensitizer under the conditions of the test.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

3.38

Test group / Remarks:

10% Concentration (% w/w) in acetone/olive oil 4:1

Results 2

Key result

Parameter:

SI

Value:

11.46

Test group / Remarks:

25% Concentration (% w/w) in acetone/olive oil 4:1

Results 3

Key result

Parameter:

SI

Value:

16.65

Test group / Remarks:

50% Concentration (% w/w) in acetone/olive oil 4:1

Any other information on results incl. tables

Table 1: Stimulation Index of the Test Item

Concentration (%w/w) in acetone/olive oil 4:1	Stimulation Index	Result
10	3.38	Positive
25	11.46	Positive
50	16.65	Positive

Applicant's summary and conclusion

Interpretation of results:

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

Conclusions:

The test material was considered to be a moderate skin sensitizer with an EC3 of 9.58% under the conditions of the test.

Executive summary:

The study was performed to the standardised guidelines OECD 429, under GLP conditions. Following a preliminary screening test in a female mouse treated with the test item at a concentration of 50% w/w in acetone/olive oil 4:1, in which no clinical signs of toxicity were noted, this concentration was selected as the highest dose investigated in the main test.

Three groups, each of five female animals, were treated with 50 μL (25 μL per ear) of the test item, as a solution in acetone/olive oil 4:1, at concentrations of 50%, 25% or 10% w/w. A further group of five female animals was treated with acetone/olive oil 4:1 alone in the same manner.

One mouse of the 50% dose group was euthanized on Day 6 due to the clinical signs of toxicity including hunched posture, emaciation, lethargy, and splayed gait.

The test material was considered to be a moderate skin sensitizer with an EC3 of 9.58% under the conditions of the test and is classified as a contact sensitizer (Category 1B) according to GHS.