Tributyl-2-methoxypropylphosphonium salt with 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis[phenol]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 June 2005 to 05 August 2005

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

The preliminary irritation study was repeated because older animals were initially assessed.Two 12-week old animals were used to restart the study and dose selection was based off these animals. Study integrity was not adversely affected by the deviation.

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

MTDID 3285

IUPAC Name:

MTDID 3285

Details on test material:

- Name of test material (as cited in study report: MTDID 3285
- Substance type: Light brown waxy chunks
- Physical state: solid
- Analytical purity: Minimum 86%
- Lot/batch no.: Lot 30045
- Expiration date of the lot/batch: 01 June 2006
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark
- Other: Molecular weightL 610; pH (1% in water) 9.8

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA inbred, SPF-Quality

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L'Arbresie Cedex, France
- Age at study initiation: 11-12 weeks old
- Weight at study initiation: 20-28 grams
- Housing: individual housing in labeled Macrolon cages with sterilized sawdust as bedding material.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days before the start of treatment
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.6-22.2 degrees C
- Humidity (%): 25-80% (above optimum conditions but not expected to affect study integrity)
- Air changes (per hr): 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light/ 12 hours dark
IN-LIFE DATES: From: 06 June 2005 To: 28 June 2005

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

10%, 25% and 50% test article concentrations in the vehicle. The vehicle alone was administered to the control groups.

No. of animals per dose:

5 animals per group (4 groups total)

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: The compound is soluble in the vehicle
- Irritation: The animals had a irritation score of 1 for dorsal surface erythema when treated with concentrations of 25% and 50% test substance.
- Lymph node proliferation response: This response was not studied in the preliminary irritation study.
MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT: 5 animals were assigned to four groups consisting of a control group, 10%, 25% and 50% test article concentration.
- Name of test method: mouse local lymph node assay
- Criteria used to consider a positive response: A Stimulation Index (the ratio of DPM/group compared to DPM/vehicle) greater than or equal to three is regarded as a skin sensitiser.
TREATMENT PREPARATION AND ADMINISTRATION: One group of five animals was treated with the vehicle (group 1). Three groups of five animals were treated with one test substance concentration (groups 2, 3, 4 treated with 10%, 25% and 50% test article). The dorsal surface of both ears was epidermally treated (25 microliters/ear) with the test substance concentration, at approximatly the same time each day for days 1, 2 and 3. The control group was treated the same way with a vehicle. On day 6, all animals were injected via the tail vain with 0.25 ml of sterile phosphate buffered saline (PBS) contained 20 microCi of 3H-methyl thymidine. After five hours, all animals were killed by intraperiotneal injection with pentobarbital. The draining lymph node of each ear was excised. The relative size of the nodes was estimated by visual examination and the abnormalities of the nodes surrounding area was recorded. The nodes were pooled for each animal in approximatrely 3 ml PBS.

Positive control substance(s):

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

Statistics:

Radioactive measurements were performed using a scintillation counter tousing a statistical precision of +/- 0.2% or a maximum of 5 minutes, which ever comes first.

Results and discussion

Positive control results:

The six monthly reliability check with hexyl cinnamic aldehyde indiciated that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitiivty.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: The SI (+/- standard deviation) for groups 1, 2, 3, and 4 were 1.0, 1.1 (+/- 0.6), 3.7 (+/- 0.5), 4.9 (+/- 0.6), respecitively.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Control group DPM ranged from 141 to 406 DPM. Group 2 DPM ranged from 126 to 424 DPM. Group 3 DPM ranged from 541 to 1196 DPM and group 4 DPM ranged from 627 to 1934 DPM. Mean DPM +/- the standard deviation was 242 +/- 104, 267 +/-111, 888 +/- 276, 1175 +/- 562 DPM for groups 1, 2, 3, 4 respectively.

Any other information on results incl. tables

Irritation of the ears shown by animals was considered not to have a toxicologically significant effect on the activity of the nodes. The majority of nodes were considered normal in size, except for the nodes of one animal treated at 50% test substance concentration, which were increased in size. No macroscopic abnormalities were observed. There were no toxicologically significant effects in body weight change. No signs of systemic toxicity or mortality were observed in the animals.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: other: OECD GHS and EC Criteria for classfication and labeling requirements for dangerous substances and preparations

Conclusions:

The SI values calculated for the substance concentrations 10, 25, and 50% were 1.1, 3.7 and 4.9, respectively. These results indicate that the test substance could elicit a SI >3. The data showed a dose response and an EC3 value of 21%.The six monthly reliability check with hexyl cinnamic aldehyde indiciated that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitiivty. Based on these results, according to the recommendations made in test guided, the test substance would be regarded as skin sensitizer. According to Globally Harmonized System of Classification and Labeling of Chemicals of the United Nations, the test article should be classified as a skin sensitizer (category 1). According to the EC criteria for classification and labeling requirements for dangerous substance and preparations, the test article should be labled as "may cause sensitization by skin contact (R43)".

Executive summary:

The contact hypersensitivity of the test article in the mouse using a local lymph node assay (LLNA) was assessed. The study was carried out using the guidelines described in OECD 429, EC, Council Directive 67/548/EEC, Annex V, B.42 (2004) and EPA OPPTS 870.2600 (2003) "Skin Sensitization." Test substance concentrations selected for the main study were based on the results of a preliminary study. In the main study, three groups of five experimental animals were epidermally exposed to 10%, 25% or 50% concentrations of the test substance in vehicle for three consecutive days. Five vehicle control animals were similarly treated, but with the vehicle (dimethyl formamide) alone. Three days after the last exposure, all animals were injected with 3H-methyl thymidine after five hours the draining (auricular) lymph nodes were excised. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index is calculated for each group. The skin effects seen after the third epidermal exposure caused irritation of the ears and considered not to have a toxicologically significant effect on the activity of the nodes. The majority of nodes were considered normal in size, except for the nodes of one animal treated at 50% test substance concentration, which were increased in size. No macroscopic abnormalities of the surrounding area were noted. Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25, and 50% were 267, 888 and 1175, respectively. The mean DPM/animal value for the vehicle control group was 242. The SI values calculated for the substance concentrations 10, 25, and 50% were 1.1, 3.7 and 4.9, respectively. These results indicate that the test substance could elicit a SI >3. the data showed a dose response and an EC3 value of 21%. The six monthly reliability check with hexyl cinnamic aldehyde indicated that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity. Based on these results, according to the recommendations made in test guidelines, the test substance would be regarded as skin sensitizer. According to Globally Harmonized System of Classification and Labeling of Chemicals of the United Nations, the test article should be classified as a skin sensitizer (category 1). According to the EC criteria for classification and labeling requirements for dangerous substance and preparations, the test article should be labeled as "may cause sensitization by skin contact (R43)".