4-[(4-HYDROXYPYRIMIDIN-2-YL)AMINO]BENZONITRILE

Endpoint summary

Description of key information

Skin sensitisation:

In a Local Lymph Node Assay (LLNA) in mice (CBA/Ca strain) equivalent to OECD 429 and according to SPL Standard Test Method 595.12, the test item was observed to be non-sensitizing to the skin.

An in vitro or in chemico skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study (initiated before October 11th 2016) is available.

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:

2004-11-01 to 2004-12-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: SPL Standard Test Method 595.12

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

The assay determines the level of lymphocyte proliferation in lymph nodes draining the application site of the test material. Determination of lymphocyte proliferation is quantified by measuring the incorporation of radiolabeled thymidine in the dividing lymph node cells. The proliferation response of lymph node cells was expressed as the number of radioactive disintegrations per minute per lymph node (dpm/node) and as the ratio of 3HTdR incorporation into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index).

GLP compliance:

no

Remarks:

The study was conducted in a facility operating to Good Laboratory Practice within the UK national GLP monitoring programme, but the study report had not been audited by the QA Unit. No formal claim of GLP compliance was made for the study.

Type of study:

mouse local lymph node assay (LLNA)

Specific details on test material used for the study:

- Name of test material (as cited in study report): T2487

Species:

mouse

Strain:

other: CBA/Ca

Sex:

not specified

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: no data
- Weight at study initiation: 16 to 21 grams
- Housing: no data
- Diet (e.g. ad libitum): no data
- Water (e.g. ad libitum): no data
- Acclimation period: no data


ENVIRONMENTAL CONDITIONS: no data

IN-LIFE DATES: no data

Vehicle:

dimethylformamide

Concentration:

vehicle alone, 0.5%, 1% and 2.5% w/w

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: no data
- Irritation: no data
- Lymph node proliferation response: no data
- other: Following a preliminary sighting test, no signs of systemic toxicity were observed at a concentration of 2.5% w/w.


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: a stimulation Index of greater than 3.0


TREATMENT PREPARATION AND ADMINISTRATION:
- Three groups, each of 4 animals, were treated with 50 uL (25 uL per ear) of the test substance as a solution in dimethyl formamide at concentrations of 0.5%, 1% and 2.5% w/w. A further group of four animals was treated with dimethyl formamide alone.

Positive control substance(s):

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

other: 2,4 Dinitrobenzenesulfonic acid, sodium salt, at 1%, 10%, 20% v/v in 1% pluronic F-68 in distilled water

Positive control results:

See field 'Any other information on results incl. tables)

Parameter:

SI

Value:

1.15

Test group / Remarks:

0.5% w/w group / mean results of 4 animals

Parameter:

SI

Value:

1.3

Test group / Remarks:

1% w/w group / mean results of 4 animals

Parameter:

SI

Value:

0.96

Test group / Remarks:

2.5% w/w group / mean results of 4 animals

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA
Dpm/Node obtained by dividing Dpm value by 8 (total number of lymph nodes):
Vehicle control group: 532.54
0.5 % w/w group: 610.17
1 % w/w group: 692.79
2.5 % w/w group: 512.43

DETAILS ON STIMULATION INDEX CALCULATION
The Stimulation Index (SI) expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group is reported for each test group in the results table above

EC3 CALCULATION
No EC3 value could be calculated as the mean SI values for each group were below 3.

CLINICAL OBSERVATIONS:
No signs of systemic toxicity

BODY WEIGHTS
Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

Positive Control Local Lymph Node Assay in the Mouse (2004)

Start Date	Finish Date	Test Material	Concentration	Vehicle	Stimulation Index^a	Classification^b
29/04/2004	05/05/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.40, 2.23, 6.09	Positive
29/04/2004	05/05/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	acetone/olive oil 4:1	1.74, 2.20, 8.89	Positive
14/10/2004	26/10/2004	α‑Hexylcinnamaldehyde, tech., 85%	5%, 10%, 25% v/v	tetrahydrofuran	1.97, 3.71, 7.82	Positive
29/09/2004	05/10/2004	2,4‑Dinitrobenzenesulfonic acid, sodium salt	1%, 10%, 20% v/v	1% pluronic F-68 in distilled water	1.03, 4.41, 13.55	Positive
27/10/2004	02/11/2004	α‑Hexylcinnamaldehyde, tech., 85%	10%, 25%, 50% v/v	cottonseed oil	1.52, 2.63, 5.07	Positive

a=        Ratio of test to control lymphocyte proliferation

b=        Stimulation index greater than 3.0 indicates a positive result

* =        Standard Test Method 595 (Pooled nodes)

·=        Standard Test Method 599 (Individual nodes)

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was considered to be a non-sensitiser under the conditions of the test.

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Skin sensitisation:

Sanders (2004) assessed the skin sensitisation potential of the test item using the Local Lymph Node Assay in CBA/Ca strain of mouse. The test was designed to assess the skin sensitising potential (delayed type hypersensitivity) of the test item following topical application to the dorsal surface of the ear. Primary lymphocyte proliferation is assessed during the sensitising (induction) phase of the response.

Following a preliminary sighting test, at which there were no signs of systemic toxicity at a concentration of 2.5% w/w, three groups, each of four animals, were treated with 50 μl (25 μl per ear) of the test material as a solution in dimethyl formamide at concentrations of 0.5%, 1% and 2.5% w/w. A further group of four animals was treated with dimethyl formamide alone.

No test item related clinical signs, body weight changes, nor mortality were observed. The Stimulation Index (SI) was

0.5% w/w dose group: 1.15 (negative)

1% w/w dose group: 1.30 (negative)

2.5% w/w dose group: 0.96 (negative)

The radioactive disintegrations per minute (dpm) per lymph node was: 

vehicle control group: 532.54

0.5% w/w group: 610.17

1% w/w group: 692.79

2.5% w/w group: 512.43

The test item was considered to be a non-sensitizer under the conditions of the test.

An in vitro or in chemico skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study (initiated before October 11th 2016) is available.

Justification for classification or non-classification

Skin sensitisation:

Based on the results of the available K1 study (Sanders, 2004), T002487 would not be regarded as a skin sensitizer according to the recommendations made in the test guidelines. The test item does not have to be classified and has no obligatory labelling requirement for sensitization by skin contact according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments).

Respiratory sensitisation:

No data were available on respiratory sensitization to decide on the classification for this endpoint.