2-(chloromethyl)-4-methylquinazoline

Endpoint summary

Description of key information

In an LLNA Test according to OECD 429 a significant lymphoproliferative response (SI > 3) was observed at all of the applied concentrations. Thus, the test item has the potential to cause skin sensitisation and is considered to be a strong sensitiser requiring classification as a Category 1 (Sub-category 1A) skin sensitiser.

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:

2006-11-26 to 2006-12-05

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)

Version / remarks:

2002

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2004

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
- Source: WOBE Kerekedelmi Kft., H-1164, Budapest, Garmada u. 10.
- Age at study initiation: Young adult, 10-11 weeks old
- Weight at study initiation: The weight variation in animals involved in the study did not exceed +-20% of the mean weight
- Housing: Group caging (4 animals/cage)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 35 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +-3°C
- Humidity (%): 30-70%
- Air changes (per hr): 8-12 per hr
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

Vehicle:

dimethylformamide

Concentration:

2.5; 5; 10; 25; 50 % (w/v)

No. of animals per dose:

4 animals

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: Solubility of the test item was determined in a preliminary test. The test item proved to be soluble in Acetone: Olive oil mixture (4:1, AOO) with a maximum concentration of 25 %(w/v) and in Dimethylformamide (DMF) with a maximum concentration of 50 %(w/v) (100% was not available). To apply the maximum available concentration, DMF was selected as solvent of the test item.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Proliferation Assay
- Criteria used to consider a positive response: The test item is regarded as a sensitiser if the following criteria are fulfilled: That exposure to at least one concentration of the test item results in an incorporation of 3HTdR at least 3-fold or greater than recorded in control mice, as indicated by the stimulation index (SI). The data are compatible with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local toxicity or immunological suppression.

TREATMENT PREPARATION AND ADMINISTRATION:

Preparation of the Animals: The animals were randomised and allocated to the experimental groups. The randomisation was checked by computer software according to the actual body weights, verifying the homogeneity and deviations between the groups.

Administration of the Test Item: Each mouse was topically dosed with 25 µl of the appropriate formulation using a pipette to apply the sample on the dorsal surface of each ear. Each animal was dosed on three consecutive days (Day 0, 1 and 2). There was not treatment on days 3 and 4.

Positive control substance(s):

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

Positive control results:

The Stimulation Index (SI) values with the known sensitiser a-Hexylcinnamaldehyde at 25% confirms the validity of the test method.

Parameter:

SI

Value:

1

Test group / Remarks:

Negative control (DMF)

Parameter:

SI

Value:

36.1

Test group / Remarks:

2.5%

Parameter:

SI

Value:

28.2

Test group / Remarks:

5%

Parameter:

SI

Value:

35.6

Test group / Remarks:

10%

Parameter:

SI

Value:

46.8

Test group / Remarks:

25%

Parameter:

SI

Value:

46.5

Test group / Remarks:

50%

Cellular proliferation data / Observations:

(Group DPM = Measured DPM(group) values - average DPM(background) values):
Group DPM: 2591.0 (Negative control); 93565.2 (2.5%); 73058.1 (5%); 92319.2 (10%); 121342.9 (25%); 120463.5 (50%)

The EC3 value between the control value and the first measured SI values (2.5%, 5% and 10% respectively) is much lower than 1 using a linear regression between these values.

Clinical Signs and Mortality

No mortality or systemic clinical signs of toxicity were observed during the study. No cutaneous reactions were observed at the treated site, either in the control groups or in any of the test item treated groups. No treatment related effects on animal body weights were observed.

Other Observations

Precipitation of the test item was observed on the ears of animals after the treatment at concentration of 50 %, 25 % and 10 %. The visible degree of the precipitation was in proportion to the test item concentration. Only slight precipitation was observed at concentration of 10%. The time of appearance of precipitation was about 5, 10 and 15 minutes after the treatment at concentrations of 50 %, 25 % and 10 %, respectively.

Interpretation of Observations

There were no confounding effects of irritation or toxicity, so the proliferation values are considered to reflect the real potential of the test item to cause lymphoproliferation in this Local Lymph Node Assay. Stimulation index values showed that precipitation observed at higher concentrations had no considerable influence on the efficiency of absorption of the test item through the skin. Lymphoproliferative responses observed at all of the applied test item concentrations (including concentrations with precipitation) are considered to be good evidence that the test item is a potential, strong sensitiser.

Interpretation of results:

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

Conclusions:

A significant lymphoproliferative response (SI > 3) was observed at all of the applied concentrations. Thus, the test item has the potential to cause skin sensitisation and is considered to be a strong sensitiser requiring classification as a Category 1 (Sub-category 1A) skin sensitiser.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The test item was tested in a LLNA test in accordance with OECD 429 and in compliance with GLP using concentrations of 2.5, 5, 10, 25, and 50%. These resulted in stimulation index values (SI) of 36.1, 28.2, 35.6, 46.8, and 46.5. This is clearly above the SI of 3 required for classification. Therefore, classification as a skin sensitiser is required. No estimated EC3 value was given in the study, however the SI values indicate that the EC3 value is below the cut-off of 2%. Therefore the substance is considered to be a strong sensitiser requiring classification as a Category 1 (Sub-category 1A) skin sensitiser.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

no data

Justification for classification or non-classification

A significant lymphoproliferative response (SI > 3) was observed at all of the applied concentrations. No estimated EC3 value was given in the study, however the SI values indicate that the EC3 value is below the cut-off of 2%. Thus, according to CLP Regulation (1272/2008) the substance is classified as skin sensitising Category 1A, H317 (may cause an allergic skin reaction).