{[(2,4 and 2,5 and 2,6)-dimethylphenyl and 2-ethylphenyl]amino}{[(2,4 and 2,5 and 2,6)-dimethylphenyl and 2-ethylphenyl]amino}methaniminium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

From 28 November 2012 to 30 November 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This read-across is based on the hypothesis that the source and the target substance have similar structural formula, with a similar toxicity profile amongst the raw materials used to synthetized the Sepisol Fast Yellow MG-F and MG-DPG. The target substance is a UCVB characterized qualitatively but not quantitatively, i.e. exact distribution of the various species is not well known. The UVCB is composed of a common core which is identical to the mono-constituent source substance. The source and the target substances share structural similarities with common functional groups varying in their substitutions. Adequate, reliable and available scientific information indicates that the source and target substances would have similar toxicity profiles. Both substances are manufactured according the same manufacturing process, with the same facilities, and will be handled and use in the same ways. The exposure to these 2 substances will be also identical. The source and target substances are also classified in the same way, with the same labelling requirements. Therefore, read-across from the existing skin irritation test on the source substance is considered as an appropriate adaptation to the standard information requirements of Annex VII, 8.1 of the REACH regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH regulation.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The basic structures of the target and the source substances are the same: the target substance is the source substance which is substituted on the phenylamine cycles by 2 methyl groups or 1 ethyl group (see Figure I in the document attached).
Remark: the target and the source substances are manufactured by the same manufacturer, within the same facilities, and the anionic starting raw material used for the synthesis is identical.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source substance (Sepisol fast yellow MG-DPG) and the target substance (Sepisol fast yellow MG-F) share the same impurities and a very close physicochemical properties profile (see table 3 of the attached document)


3. ANALOGUE APPROACH JUSTIFICATION
All the physicochemical properties were determined thank to same method for the 2 sources, and their profile is similar (see attached document). The structural differences in the substitution of the diphenylamine cycles do not significantly influence the physicochemical properties. However, some trends in the physicochemical parameters due to the substitution of the cycles can be observed : for example, while a clear and sharp melting point is observed at 160°C for the source substance (mono-constituent), a softening point with no clear melting is observed at 130°C for the target substance (UVCB). It is consistent with the fact that when substances with close melting point are mixed together, the mixture has a lowered melting point and a broadened melting range.
The solubility of the target substance is lower than the solubility of the source substance, which is consistent with the increase of its molecular weight. The partition coefficient has been calculated from the measured solubilities of the test item in octanol and in water separately: the one of the target substance is higher than the one of the source substance (higher molecular weight so lower solubility and high solubility in octanol) but it remains under the cut-off value of 4.

Comparison of the results of the acute toxicity test performed on the source and the target substance are detailled in the attached document: both have a LD50 between 300 mg/kg and 2000 mg/kg and are classification acute toxicity oral cat. 4.

4. DATA MATRIX
See the attached document.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD guideline 439 (In-vitro skin irritation)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU method B.46 (In vitro skin irritation)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

941-151-0

EC Number:

941-151-0

IUPAC Name:

941-151-0

Constituent 2

Reference substance name:

anilino(phenylimino)methanaminium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate

IUPAC Name:

anilino(phenylimino)methanaminium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate

Constituent 3

Reference substance name:

Sepisol Fast Yellow MG-DPG

IUPAC Name:

Sepisol Fast Yellow MG-DPG

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report):Sepisol Fast Yellow MG-DPG
- Substance type: Organic salt
- Stability under test conditions: Stable
- Storage condition of test material: Room temperature

Test animals

Species:

human

Strain:

other: reconstructed epidermis of normal human keratinocytes.

Details on test animals or test system and environmental conditions:

TEST SYSTEM
- Source: Skinethic Laboratories - 4 rue Alexander Fleming - 69366 Lyon CEDEX 07.
- Cell system used: reconstructed epidermis of normal human keratinocytes. Cells are grown on inert polycarbonate filter on chemically defined medium, arilifted for 17 days.
- RhE model : SkinEthic RHE/S/17
- Lot/Batch No.: 12 022A 1103

Test system

Type of coverage:

open

Preparation of test site:

other:

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

16 mg applied as such to the epidermal surface

Duration of treatment / exposure:

not applicable

Observation period:

not applicable

Number of animals:

not applicable

Details on study design:

I- TEST SYSTEM

Units of 0.50 cm² reconstituted epidermis (SkinEthic) were received on the day before the experiment. The insert (filter + epidermis) was gently removed from the agarose while avoiding leaving agarose on the polycarbonate filter.

II- CHECK OF THE COMPATIBILITY OF THE TEST ITEM (direct MTT reduction, coloring potential, ability to stain tissues) WITH MTT SOLUTION

Prior to experiment, 16 mg of the test item was put in contact with 300 µL of MTT solution (1 mg/mL). After a 3 hrs incubation period at 37°C, 5% CO2, no blue or purple coloration was noted.

Therefore, there is no direct interaction between the test item and MTT.

III- APPLICATION OF THE TEST AND CONTROL CHEMICALS

* For all steps of the protocol, one 24 wells plate (3 columns of 4 wells) was used for each item (the test item, the negative control and the positive control).

* The insert were placed in a 24 wells culture plated which has been previously filled with 300 µL of maintenance medium (Batch No. 12 011J-M 037).

* 3 units of reconstructed human epidermis were used for the test item, the negative and positive controls.

* For the test item: 16 mg was applied as such to the epidermal surface of the models. For the positive control: unspecified quantity of 5% SDS (CAS N° 151-21-3, Sigma Batch N° BCBF8969V) were applied to uniformly cover the epidermis surface. For the negative control: unspecified quantity of PBS (Pan Biotech GmbH – Batch N° 2020312) were applied to uniformly cover the epidermis surface.

* At the end of an exposure period of 42 min at room temperature, the human epidermis was washed with 25 x 1 mL of PSB (PAN BIOTECH GmbH, Batch n° 2020312) except for the three epidermises treated with the test item wich were rinces with 35 x 1 mL of PBS. Even after this rinse, there was remaining test item on the surface of the three epidermises.

* Rinsed epidermis were incubated in fresh medium for a 42 hours 10 min post-treatment incubation period at 37°C, 5% CO2.

* Then, the epidermis were put in contact with the MTT solution.

IV-CELL VIABILITY MEASUREMENTS

* After the 42h10min incubation period, the cell viability was quantified by measurement of the cell succinate dehydrogenase activity. The skin sample was placed in 300 µL of a MTT solution of 1 mg/mL concentration for 3 hours at 37°C, 5% CO2. The precipitated blue formazan product is then extracted using isopropanol during 2 hours under agitation in the dark, and the concentration of formazan was measured by determining the Optical Density (OD) at 570 nm, just after dilution of the extractions in isopropanol (1:2).

The absorbance was measured in triplicate of MTT extract.

The optical density was performed usgin the ELx800 absorbance microplate reader and the validated software Gen5ELISA V1.05.11

V- INTERPRETATION OF RESULTS

* The results were expressed as a viability percentage compared with the negative control :

Viability %= [OD (test item)/OD (negative control)] ×100

The optical density (OD) values obtained for each test sample were used to calculate a percentage of viability relative to the negative control, which was arbitrarily set at 100%.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: cell viability percentage

Value:

ca. 86.3

Remarks on result:

other:

Remarks:

Basis: mean. (migrated information)

Any other information on results incl. tables

Individual and average values of OD after 42 minutes of exposure:

	Skin	OD	Mean OD/disc (Mean of the 3 OD measurements)	Mean OD/ product	Viability %	Mean Viability %	SD	Conclusion
Negative Control	1	1.041 1.100 1.138	1.093	1.031*	106.0	100.0	5.9
	2	0.961 1.039 1.092	1.030		99.9
	3	0.908 0.976 1.029	0.971		94.1
Positive Control	4	0.012 0.014 0.013	0.013	0.013	1.3	1.2	0.1	Irritant
	5	0.011 0.013 0.012	0.012		1.2
	6	0.013 0.012 0.014	0.013		1.3
Test Item	7	0.216 0.243 0.250	0.236 – Aberrant values
	8	0.763 0.761 0826	0.783	0.890	76.0	86.3*	14.6*	Non irritant
	9	0.918 1.030 1.040	0.996		96.6

* The result is based on two tissues replicates (n° 8 and 9) instead of three as initially scheduled in the study plan. The rinsing of the epidermises in view to eliminate the test item after treatment was difficult and required more rinsing with PBS than usually. The first treated epidermis was compromised during this rinsing step and was not taken into account for the classification of the test item.

                 

Negative control and positive control are in the expected range

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The results obtained under these experimental conditions, enable to conclude that the test item must not be classified, according to the criteria for classification, packaging and labelling of dangerous substances and preparations in compliance with the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol or risk phrase is required.
In accordance with the Regulation EC No. 1272/2008, the test item must not be classified. No signal word or hazard statement is required.

Executive summary:

The aim of the study was to evaluate the possible irritating effects of SEPISOL FAST YELLOW MG-DPG after topical administration on in vitro human reconstructed epidermis (RHE® model). The test item SEPISOL FAST YELLOW MG-DPG was applied, as supplied, at the dose of 16 mg, to 3 Reconstructed Human epidermis small during 42 minutes, followed by a 42 hours post-incubation period at 37°C, 5% CO2.

The elimination of the test item on the epidermis after treatment was difficult. Even after a rinse with 35 mL of PBS, there was remaining test item. The first epidermis was compromised during rinsing and was not taken into account for the classification of the test item.

The experimental protocol was established in accordance with OECD guideline No. 439 adopted 22 July 2010 and the Test method B.46 of Council regulation No. 761/2009 dated 23 July 2009 (EU Journal L220)-ATP Council regulation No. 4401/2008 of 30 May 2008 (E. U. Journal L142).

The mean viability ofthe epidermis skins was 86.3%, versus 1.2% in the positive control (5% Sodium Dodecyl Sulfate ).

The results obtained, under these experimental conditions, enable to conclude that the test item SEPISOL FAST YELLOW MG-DPG must not be classified, according to the criteria for classification, packaging and labelling of dangerous substances and preparations in compliance with the E.E.C. Directives 67/548, 2001/59 and 99/45. No symbol or risk phrase is required.

In accordance with the Regulation EC No. 1272/2008, the test item must not be classified. No signal word or hazard statement is required.