1,1,2-trimethyl-3-(4-sulphonatobutyl)-1H-benz[e]indolium

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

April 2002

Deviations:

yes

Remarks:

Temporary deviations from the minimum level of temperature occurred. Evaluation: Laboratory historical data do not indicate an effect of the deviations

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 2008

Deviations:

yes

Remarks:

Temporary deviations from the minimum level of temperature occurred. Evaluation: Laboratory historical data do not indicate an effect of the deviations

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

March 2003

Deviations:

yes

Remarks:

Temporary deviations from the minimum level of temperature occurred. Evaluation: Laboratory historical data do not indicate an effect of the deviations

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

1,1,2-trimethyl-3-(4-sulphonatobutyl)-1H-benz[e]indolium

EC Number:

263-961-7

EC Name:

1,1,2-trimethyl-3-(4-sulphonatobutyl)-1H-benz[e]indolium

Cas Number:

63149-24-6

Molecular formula:

C19H23NO3S

IUPAC Name:

1,1,2-trimethyl-3-(4-sulfobutyl)-1H-benzo[e]indol-3-ium

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

Mouse: CBA strain, inbred, SPF-Quality.
Recognized by the international guidelines as the recommended test system (e.g. OECD, EC, EPA). Source: Charles River France, L’Arbresle Cedex, France.
Age and bodyweight Young adult animals (approx. 10 weeks old) were selected. Body ,weight variation was within +/- 20% of the sex mean.
Identification: Tail mark with marker pen.
A health inspection was performed prior to treatment, to ensure that the animals are in a good state of health. Special attention was paid to the ears, which were intact and free from any abnormality.

Conditions
Animals were housed in a controlled environment, in which optimal conditions were considered to be approximately 15 air changes per hour, a temperature of 21 .0 +- 3.0°C (actual range: 17.7 - 23.9°C), a relative humidity of 30-70% (actual range: 32 - 53%) and 12 hours artificial fluorescent light and 12 hours darkness per day.

Accommodation
Individual housing in labeled Macrolon cages (Ml type; height 12.5 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France). Paper (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom) 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.

Acclimatization period
The acclimatization period was at least 5 days before the start of treatment under laboratory conditions. Accommodation was as described above except that the animals were group housed in Macrolon cages (Mlll type; height 18 cm).

Diet
Free access to pelleted rodent diet (SM R/M-Z from SSNlFF® Spezialdiaten GmbH, Soest,
Germany).

Water
Free access to tap water.

Results of analysis for each batch of diet (nutrients and contaminants), sawdust, paper and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

0%, 10%, 25% and 50% of test substance

No. of animals per dose:

5

Details on study design:

Three groups of five animals were treated with three test substance concentrations respectively. One group of five animals was treated with vehicle.

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

2.3

Test group / Remarks:

Concentration of 10% test substance

Results 2

Parameter:

SI

Value:

3.1

Test group / Remarks:

Concentration of 25% test substance

Results 3

Parameter:

SI

Value:

5.7

Test group / Remarks:

Concentration of 50% test substance

Results 4

Parameter:

EC3

Value:

23.3

Test group / Remarks:

23.3% of test substance

Cellular proliferation data / Observations:

Skin reactions & Irritation:
No irritation of the ears was observed in any of the animals examined. For the animals treated with 50%, no scoring for erythema was possible due to blue staining by the test substance.

Macroscopy of the auricular lymph nodes and surrounding area:
All nodes were considered normal in size, except for one node of one animal at a 50% test substance concentration which was increased in size. No macroscopic abnormalities of the surrounding area were noted.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

The SI values calculated for the substance concentrations 10, 25 and 50% were 2.3, 3.1 and 5.7 respectively.
These results indicate that the test substance could elicit an SI 2 3. The data showed a dose-response and an EC3 value (the estimated test substance concentration that will give a SI =3) of 23.3% was calculated.

Based on these results:
- according to the recommendations made in the test guidelines, SULFOBUTYL TMBl would be regarded as skin sensitizer.
- according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (2007), SULFOBUTYL TMBI should be classified as skin sensitizer (Category 1).
- according to the EC criteria for classification and labeling requirements for dangerous substances and preparations (Council Directive 67/548/EEC), SULFOBUTYL TMBI should be labeled as: may cause sensitization by skin contact (R 43).
- according to the Regulation (EC) No 1272/2008 on classification, labeling and packaging of substances and mixtures, SULFOBUTYL TMBI should be classified as skin sensitizer (Category 1) and labeled as H317: May cause an allergic skin reaction.