α,α,α-trifluoro-o-toluidine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 10 may 2006 to 27 march 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was performed according to the standardised method (OECD guideline 429), well described, but not GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

α,α,α-trifluoro-o-toluidine

EC Number:

201-806-7

EC Name:

α,α,α-trifluoro-o-toluidine

Cas Number:

88-17-5

Molecular formula:

C7H6F3N

IUPAC Name:

2-(trifluoromethyl)aniline

Constituent 2

Reference substance name:

alpha,alpha,alpha-trifluoro-o-toluidine

IUPAC Name:

alpha,alpha,alpha-trifluoro-o-toluidine

Details on test material:

Name: orthotrifluoromethylaniline pure
Synonym: 2-Aminobenzotrifluoride pure grade
Batch number at receipt: CHH0K001
Batch number on the analytical certificate: CHHDKA001
Both batch numbers refer to the same product.
CAS: 88-17-5
Appearance: colorless liquid
Date of receipt: 120 june 2006
Storage conditions: at room temperature

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: 8 to 12 weeks old
- Weight at study initiation: 18 to 25 g and within a range of +/- 20% of the mean body weight
- Housing: the animals will be individually housed in disposable crystal polystyrene cages (22.0 cm x 8.5 cm x 8.0 cm).
- Diet: All animals will have free access to SSNIFF R/M-H pelleted diet (SSNIFF Spezialdiäten GmbH, Soest, Germany)
- Water: tap water (filtered using a 0.22 micron filter) contained in bottles
- Acclimation period: at least 5 days before the begginning of the study.

ENVIRONMENTAL CONDITIONS
- temperature : 22 ± 2°C,
- relative humidity: 30 to 70%,
- light/dark cycle: 12 h/12 h,
- ventilation: approximately 12 cycles/hour of filtered, non-recycled air.


IN-LIFE DATES: from 26 december 2006 to 09 january 2007

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

25, 50 and 100%

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: test item was freely soluble in the vehicle
- Irritation: non irritant
- Lymph node proliferation response: no

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- animals were assigned to the treatment groups by hand procedure.
Identification: individually by a number on the tail using an indelible marker.
- Criteria used to consider a positive response: The test item should be regarded as a skin sensitizer when the SI for a dose group is >=3. Other relevant criteria such as cellularity, radioactivity levels and ear thickness will be also taken into account to evaluate the data. When appropriate, the EC3 value (theoretical concentration resulting in a SI value of 3) will be determined by linear interpolation of points on the dose-response curve, immediately above and below the 3-fold threshold.
The equation used for calculation of EC3 will be: EC3 = c + [(3 - d)/(b - d)] x (a - c) Where a = the lowest concentration giving stimulation > 3;
b = the actual stimulation index caused by a;
c = the highest concentration failing to produce a stimulation index of 3;
and d = the actual stimulation index caused by c.

TREATMENT PREPARATION AND ADMINISTRATION:
The animals were allocated to four groups:three treated groups (4 animals each) with the test item at concentrations of 25, 50 and 100% and one negative control group of four animals receiving the vehicle.

Positive control substance(s):

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

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: SI were 1.58, 3.32 and 4.74 at 25, 50 and 100% respectively.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Control group: 54.64 25%: 86.33 50%: 181.61 100%: 258.9

Any other information on results incl. tables

A significant lymphoproliferation was noted at concentrations of 50 and 100%.
In the absence of local irritation, the significant lymphoproliferative responses observed at the concentration of 50 and 100% were attributed to delayed contact hypersensitivity.
The EC3 value for the test item ORTHOTRIFLUOROMETHYLANILINE Pure is equal to 45%.

See following table:

Groups	1	2	3	4
Concentrations (%)	0 (Acetone/olive oil (4/1))	25	50	100
Cell count viable	77	62	126	159
Cell count dead	23	4	36	6
Viability (%)	77	93.94	77.78	96.36
Amount of cells (x10^6cells)	7.70	6.20	12.6	15.9
Cellularity index		0.81	1.64	2.06
Number of nodes per group	8	8	8	8
Disintegrations per min per gp (dpm)	437.12	690.67	1452.84	2071.23
Disintegrations per min per node (dpm)	54.64	86.33	181.61	258.9
stimulation index (SI)		1.58	3.32	4.74
Increase in ear thickness (% between day 1 and day 6)	2.91	-.98	-1.98	2
EC3 value		45%

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Orthotrifluoromethylaniline is sensitizing according to the CLP 1272/2008/EC criteria.

Executive summary:

In a dermal sensitization study (31700 TSS, CIT) with orthotrifluoromethylaniline in acetone/olive oil (4/1), young adults CBA/J female mice (4 per group), were tested using the method of LLNA.

The test item was freely soluble in the first recommended vehicle, acetone/olive oil (4/1, v/v). A solution was obtained whatever the proportion. Consequently, the concentrations selected for the preliminary test were 50 and 100%. Since the test item was non-irritant in the preliminary test, the highest concentration retained for the main test was the maximal practicable concentration (100%).

No mortality and no clinical signs were observed during the study.

No cutaneous reactions and no noteworthy increase in ear thickness were observed in the animals of the treated groups.

A significant lymphoproliferation was noted at concentrations of 50 and 100%. In the absence of local irritation, the significant lymphoproliferative responses observed at the concentration of 50 and 100% were attributed to delayed contact hypersensitivity.

The EC3 value for the test item ORTHOTRIFLUOROMETHYLANILINE Pure is equal to 45%.

Under the experimental conditions, the test item ORTHOTRIFLUOROMETHYLANILINE Pure induced delayed contact hypersensitivity in the murine local Lymph Node Assay. According to the EC3 value obtained in this experiment, the test item ORTHOTRIFLUOROMETHYLANILINE Pure should be considered as a weak sensitizer, and classified as sensitizing according to the CLP 1272/2008/EC criteria.