C.I. Pigment Violet 55

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(2010)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(2008)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

(2003)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

C.I. Pigment Violet 55

IUPAC Name:

C.I. Pigment Violet 55

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): C.I. Pigment Violet 55
- Physical state: powder

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: approx. 11 weeks old
- Weight at study initiation: 21-25 g
- Housing: Individual housing in labeled Macrolon cages (MI type; height 12.5 cm) containing sterilized sawdust as bedding material. Paper was supplied as cage-enrichment. The paper was removed on Day 1 prior to dosing and was supplied again after scoring of the ears on Day 3.
- Diet (e.g. ad libitum): Free access to pelleted rodent diet
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: 7-21 days before the start of treatment under laboratory conditions.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.4 – 23.4
- Humidity (%): 39 - 78
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

No. of animals per dose:

5

Study design: in vivo (LLNA)

Vehicle:

methyl ethyl ketone

Concentration:

Preliminary irritation study: 25% and 50%
Main test: 10%, 25%, 50%

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
As no irritation was observed, the 50% dilution was used for the main study.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymph node assay
- Criteria used to consider a positive response:
DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group.
If the results indicate a SI =/> 3, the test substance may be regarded as a skin sensitizer, based on the test guideline and recommendations done by ICCVAM.
The EC3 value (the estimated test substance concentration that will give a SI = 3) was determined, using linear interpolation.

TREATMENT PREPARATION AND ADMINISTRATION:
Test substance preparation: The test substance formulations (w/w) were prepared within 4 hours prior to each treatment. Homogeneity was obtained to visually acceptable levels.
Rationale for vehicle: The vehicle was selected based on trial formulations performed at the testing lab and on test substance data supplied by the sponsor.

Induction - Days 1, 2 and 3; Excision of nodes - Day 6; Tissue processing for radioacitivity - Day 6; Radioactivity measurements - Day 7; Performed according to test guidelines.

Observations:
Mortality/Viability: Twice daily.
Body weights: On Day 1 (pre-treatment) and Day 6.
Toxicity: At least once daily.
Irritation: On Day 3 (3-4 hours after treatment), the skin reactions were assessed according to the numerical scoring system. Furthermore, a description of all other (local) effects was recorded according to guidelines.

Positive control substance(s):

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

Statistics:

Not performed.

Results and discussion

Positive control results:

The six-month reliability check with Alpha-hexylcinnamicaldehyde indicates that the Local Lymph Node Assay as performed at the testing laboratory is an appropriate model for testing for contact hypersensitivity. See attached document 'Reliability check'.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

The SI values calculated for the substance concentrations 10, 25 and 50% were 1.8, 1.6 and 1.2, respectively. Since there was no indication that the test substance elicited a SI ≥ 3 when tested up to 50%, C. I. Pigment Violet 55 was not considered to be a skin sensitizer.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Median DPM/animal values are reported due to possible outlier responses for individual animals within groups. Median DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 1190, 1050 and 802, respectively. The median DPM/animal value for the vehicle control group was 300.

Any other information on results incl. tables

Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised and pooled for the animals.

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 (SI) was subsequently calculated for each group.

No irritation of the ears was observed in any of the animals examined.

Most auricular lymph nodes of the animals of the experimental and control groups were considered normal in size except for the nodes of one animal treated at 25% which were considered enlarged.

No macroscopic abnormalities of the surrounding area were noted for any of the animals.

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 1190, 1050 and 802 DPM, respectively. The mean DPM/animal value for the vehicle control group was 671 DPM. The SI values calculated for the substance concentrations 10, 25 and 50% were 1.8, 1.6 and 1.2, respectively.

Since there was no indication that the test substance elicited a SI ≥ 3 when tested up to 50%,

C. I. Pigment Violet 55 was not considered to be a skin sensitizer.

The six-month reliability check with Alpha-hexylcinnamaldehyde indicates that the Local Lymph Node Assay as performed at WIL Research Europe is an appropriate model for testing for contact hypersensitivity.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

Based on these results, C. I. Pigment Violet 55 would not be regarded as a skin sensitizer according to the recommendations made in the test guidelines. The test substance 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 the Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (including all amendments).

Executive summary:

An LLNA test was performed according to OECD 429 guideline and GLP principles. The majority of nodes were considered normal in size, except for one or both nodes of one animal at 10%, two animals at 25% and two animals at 50% which were considered enlarged in size. Median DPM/animal values were reported due to possible outlier responses for individual animals within groups. Median DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 797, 1674 and 1299 respectively. The median DPM/animal value for the vehicle control group was 300. The SI values calculated for the substance concentrations 10, 25 and 50% were 2.7, 5.5 and 4.3 respectively. An EC3 value of 11.6% was calculated.

Based on these results, the test substance should be classified as a skin sensitizer (category 1B) according to Regulation EC 1272/2008 .