2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[[2-methoxy-5-methyl-4-[[2-(sulfooxy)ethyl]sulfonyl] phenyl]azo]-8-[[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-, tetrasodium salt

Endpoint summary

Description of key information

Skin irritation

The dermal irritation potential of test article was determined according to the OECD 439 test guideline followed for this study. The Mean % tissue viability compared to negative control (n=3) of the test substance was determined to be 95.1 %. Thus, the test substance was considered to be not irritating to the human skin.

 

Eye irritation

Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also tend to behave in a similar manner. Therefore, the test chemical was considered to be not irritating to eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for eye irritation.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from experimental study report

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Principles of method if other than guideline:

The purpose of this study was to assess potential for the test article to be dermal irritants. The dermal irritation potential of test article may be predicted by measurement of their cytotoxic effect, as reflected in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, in the MatTek EpiDerm™ model.

GLP compliance:

no

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: as provided by MatTek In Vitro Life Science Laboratories, Bratislava, Slovakia

Source strain:

other: Not applicable

Details on animal used as source of test system:

- Description of the cell system used:The normal human-derived keratinocytes were cultured at the air-liquid interface in a chemically defined medium on a permeable polycarbonate insert (surface 0.5 cm2). They were cultured in chemically defined serum free medium to form a multi-layered epithelium similar to that found in native epidermis. Each lot of tissues was Quality Assured by MatTek according to specific QC standards including: histology, tissue viability (MTT mean optical density), reproducibility (SD) and tissue thickness.Test System IdentificationAll of the EpiDerm™ 3-dimensional human tissues used in this study were identified by the date of arrival and the lot number. Certificate of Analysis for the tissues are included in this report. Tissue plates were appropriately labeled with study information.

Justification for test system used:

The 3-Dimensional Human Dermal Epithelial Model (EpiDerm™, MatTek, In Vitro Life Science Laboratories, Bratislava, Slovakia) is made up of normal human keratinocytes in serum free medium. The cells form an epithelial tissue that consists of organized basal, spinous, granular, and cornified layers analogous to those found in vivo. The EpiDerm™ model also contains epidermis-specific differentiation markers such as pro-filaggrin, the K1/K10 cytokeratin pair, involucrin, and type I epidermal transglutaminase, as well as keratohyalin granules, tonofilament bundles, desmosomes, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns characteristic of in vivo epidermis. Each lot of tissues was Quality Assured by MatTek, Inc. according to specific QC standards including: histology (cell layers), tissue viability (MTT mean optical density) and reproducibility (SD). Tissue plates were appropriately labeled with study information. Bias was not a factor in this test system.

Vehicle:

unchanged (no vehicle)

Details on test system:

The tissues were exposed to the test article neat (undiluted) on April 25, 2018 (Run 1 of 1). EpiDerm™ tissues were purchased from MatTek. Quality control of the tissues was performed by MatTek and the Certificate of Analysis (CoA) for the tissues is provided and is kept in the study binder. Tissues were exposed for approximately 1 hour, with 35 minutes in an approximately 37°C, 5% CO2 humidified incubator and the remaining 25 minutes at room temperature. Following the exposure time, the tissues were rinsed and placed in fresh media for approximately 24 hours. The media was then changed again and the tissues were incubated in fresh media for another ~18 hours for a total of approximately 42 hour post-exposure recovery period. The tissue viability was then assessed by MTT assay. The tissue CoA was used instead of verification of barrier properties of the tissue.MTT and Color Pre-testsPretesting has actually been conducted for all chemicals, although the first intitial 8 test chemicals a pretesting was not conducted (for skin).MTT AssayFollowing the rinsing period, the MTT assay was performed by transferring the tissues to 24-well plates containing 300 µL MTT medium (1.0 mg/mL). After 3 hours MTT incubation at approximately 37°C, approximately 5% CO2 in a humidified incubator, the blue formazan salt was extracted by submerging tissues in 2 mL isopropanol in a 24-well plate. The extraction time was approximately 3 hours with gentle shaking. The optical density of the extracted formazan (200 µL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm. Relative cell viability is calculated for each tissue as % of the mean negative control tissues.Evaluation of Test Article in the Cell Models:1. Cell system: Upon receipt, the MatTek EpiDerm™ tissue cultures were placed in 0.9 mL of fresh Maintenance medium (in a 6-well plate). The culture inserts are incubated for ~one hour. The tissues were then transferred to 6-well plates containing 0.9 mL fresh Maintenance medium and they were incubated overnight (18 ± 3 hrs) at ~37°C, 5% CO2 in a humidified incubator.2. Control and Test Article Exposures: On the day of dosing, the tissues are then removed from the incubator and the controls and the test article are applied topically to tissues by pipette(liquid) Tissues were exposed to controls and the test article for one hour, with ~35 minutes in a 37°C, 5% CO2 humidified incubator and the remaining 25 minutes at room temperature.a) Controls30 µL of negative control DPBS and 30 μL of the positive control 5% SDS was applied topically to the tissue and gently spread by placing a nylon mesh on the apical surface of each tissue, if necessary.b) Test Articles 30 µL of the test article was applied topically to the tissue 3. Post-exposure treatmentAfter the 1 hour exposure, the tissues were rinsed 15 times with sterile DPBS. After the 15th rinse from washing bottle, each insert wasw completely submerge 3 times in 150 ml DPBS. The apical surface was gently blotted with a cotton swab. The tissues were placed in 0.9 mL of fresh Maintenance medium (6-well plate) for 24 ± 2 hours. After this initial ~24 hour incubation, the tissues were placed in 6-well plates containing 0.9 mL fresh Maintenance medium and incubated for another 18 ± 3 hours, for a total of an approximately 42 hour post-exposure incubation.RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE- Model used: The EpiDerm™ 3 dimensional human tissue model- Tissue Lot number(s): 26459- Date of initiation of testing: 6/08/2017TEMPERATURE USED FOR TEST SYSTEM- Temperature used during treatment / exposure: 37°C- Temperature of post-treatment incubation (if applicable): 37°CREMOVAL OF TEST MATERIAL AND CONTROLS-Volume and number of washing steps: The test substance was rinsed from the tissues with sterile DPBS by filling and emptying the tissue insert 15 times to remove any residual test material. This was followed by completely submerge the insert 3 times in 150 ml DPBS.MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE- MTT concentration: 300 µL MTT medium (1.0 mg/mL).- Incubation time: After 3 hours- Spectrophotometer: Synergy H4 spectrophotometer - Wavelength: 570 nm- Filter: No data- Filter bandwidth: No data- Linear OD range of spectrophotometer: No dataNUMBER OF REPLICATE TISSUES: 3CALCULATIONS and STATISTICAL METHODSAll data were background subtracted before analysis. MTT data are presented as % viable compared to negative control. Data were generated as follows: MTT AssayBlanks:·        The optical density (OD) mean from all replicates for each plate (ODblank). Negative Controls (NC):·        The blank corrected value was calculated: ODNC= ODNCraw– ODblank. ·        The OD mean per NC tissue was calculated. ·        The mean OD for all tissues corresponds to 100% viability. ·        The mean, standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated. Positive Control (PC):·        Calculate the blank corrected value: ODPC= ODPCraw– ODblank. ·        The OD mean per PC tissue was calculated. ·        The viability per tissue was calculated: %PC = [ODPC/ mean ODNC] x 100. ·        The mean viability for all tissues was calculated: Mean PC = Σ %PC / number of tissues. ·        The standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated. Tested compound :·        Calculate the blank corrected value ODTT= ODTTraw– ODblank. ·        The OD mean per tissue was calculated. ·        The viability per tissue was calculated: %TT = [ODTT/ mean ODNC] x 100. ·        The mean viability for all tissues was calculated: Mean TT = Σ %TT / number of tissues. ·        The standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated. Data Correction Procedure for MTT Interfering Compounds (if applicable)True viability = Viability of treated tissue – Interference from test article = ODtvt– ODktwhere ODkt= (mean ODtkt– mean ODukt).ODtvt= optical density of treated viable tissueODkt= optical density of killed tissuesODtkt= optical density of treated killed tissueODukt= optical density of untreated killed tissue (NC treated tissue) Data Correction Procedure for Colored Compounds (if applicable)True viability = Viability of treated tissue incubated in MTT media – Viability of treated tissue incubated in media without MTT = ODtvt– ODvt.ODtvt= optical density of treated viable tissue incubated in MTT mediaODvt= optical density of viable tissues incubated in media alone - Evaluation of data The results of the assay was evaluated and compared to negative control. Table: Criteria for in vitro Interpretation: In VitroResults In VivoPredictionMean tissue viability ≤50% Irritant (I), R38Mean tissue viability >50% Non-irritant (NI)- Assay quality controls- Negative Controls (NC)The Dulbecco’s phosphate buffered saline (DPBS) was used as a NC. The assay passed all acceptance criteria if the ODs of the negative control exposed tissues were between ≥0.8 and ≤2.8.  - Positive Controls (PC)5% solution of sodium dodecyl sulfate was used as a PC. The assay is meeting the acceptance criteria if the viability of the PC is ≤20% of the negative control.   - Standard Deviation (SD)The standard deviation (SD) calculated from individual percent tissue viabilities of the test article exposed replicates was ≤18.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 30 µL
- Concentration (if solution): neat

VEHICLE (Not used)
- Amount(s) applied (volume or weight with unit): none
- Concentration (if solution): none
- Lot/batch no. (if required): none- Purity: none

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL
- Concentration (if solution): neat

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL
- Concentration (if solution): 5% solution of sodium dodecyl sulfate

Duration of treatment / exposure:

The exposure times were approximately 1 hour, with ~35 minutes exposure in the incubator and ~25 minutes at room temperature.

Duration of post-treatment incubation (if applicable):

For a total of an approximately 42 hour post-exposure incubation.

Number of replicates:

3 tissues were used for test compound and control.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1

Value:

95.1

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

The MTT data show the assay quality controls were met.

Code N°	Tissue	Raw data		Blank corrected data		mean	% of viability
	n	Aliq. 1	Aliq. 2	Aliq. 1	Aliq. 2	of aliquotes
NC	1	1.7913	1.8155	1.756	1.781	1.768	92.2
	2	2.232	2.2748	2.197	2.240	2.218	115.7
	3	1.7837	1.8199	1.749	1.785	1.767	92.1
PC	1	0.0802	0.0773	0.045	0.042	0.044	2.3
	2	0.0758	0.0767	0.041	0.042	0.041	2.2
	3	0.0722	0.0695	0.037	0.035	0.036	1.9

C4	1	1.8304	1.8095	1.795	1.775	1.785	93.1
	2	1.8288	1.8401	1.794	1.805	1.799	93.8
	3	1.9588	1.9084	1.924	1.873	1.899	99.0

	mean	SD	mean of	SD	CV %
	of OD	of OD	viabilities [%]	of viabilities	[%]
NC	1.918	0.260	100.0	13.57	13.57
PC	0.040	0.004	2.1	0.21	10.02
C4	1.828	0.062	95.3	3.23	3.38

Classification
NC	NI	qualified
PC	I	qualified
C4	NI	qualified

Interpretation of results:

other: not irritating

Conclusions:

The dermal irritation potential of test article was determined according to the OECD 439 test guideline followed for this study. The Mean % tissue viability compared to negative control (n=3) of the test substance was determined to be 95.1 %. Thus, the test substance was considered to be not irritating to the human skin.

Executive summary:

The dermal irritation potential of test article was determined according to the OECD 439 test guideline for this study. The MatTek EpiDerm™ model was used to assess the potential dermal irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to the test article and controls for ~one hour, followed by a 42 hour post-exposure recovery period. The viability of each tissue was determined by MTT assay.  The MTT data show the assay quality controls were met and passed the acceptance of criteria. The Mean % tissue viability compared to negative control (n=3) of the test substance was determined to be 95.1%. Hence, under the current experimental test conditions it was concluded that test substance was considered to be not irritating to human skin and can thus be classified as “Not Classified'' as per CLP Regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

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

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data from various test chemicals

Justification for type of information:

Data is summarized based on the available information from various test chemicals.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

WoE report is based on 2 eye irritation studies as- WoE-2 and WoE-3.
Eye irritation study of test chemical was conducted rabbits to assess its eye irritating effects.

GLP compliance:

not specified

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

not specified

Vehicle:

other: 2. aqueous suspension 3. not specified

Controls:

not specified

Amount / concentration applied:

2. 2 instillations of 10% (0.2ml)
3. No data available

Duration of treatment / exposure:

2. 24 hours
3. No data available

Observation period (in vivo):

2. The test substance was installed into conjunctival sac of rabbits 5 times per week for 4 weeks.
3. No data available

Number of animals or in vitro replicates:

no data available

Details on study design:

2. - Area of exposure: conjunctival sac of rabbits
3. No data available

Irritation parameter:

overall irritation score

Remarks:

2

Basis:

mean

Time point:

other: 4 weeks

Reversibility:

fully reversible within: 24 Hours

Remarks on result:

no indication of irritation

Irritation parameter:

overall irritation score

Remarks:

3

Basis:

mean

Time point:

other: not specified

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

2. Only minimal irritative effects after 2 hours.
3. No signs of irritation observed

Other effects:

no data

Interpretation of results:

other: Not irritating

Conclusions:

Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also tend to behave in a similar manner. Therefore, the test chemical was considered to be not irritating to eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for eye irritation.

Executive summary:

The ocular irritation potential was assessed based on the available results from the in-vivo studies for the given test chemical.These studies have been summarized as below -

 

The local eye irritative potential of test chemical was investigated in rabbits’ eye to assess the degree of eye irritancy caused by the chemical. Each rabbit received 2 installation of 0.2 ml of a 10% test chemical aqueous suspension into the conjunctival sac of rabbits 5 times per week for 4 weeks. The chemical produced only minimal irritating effects after 2 hours which could not confirmed the irritation potential. Hence, on the basis of findings the Test chemical can be considered as not irritating to the rabbits’ eye.

 

The above study is supported with another eye irritation study conducted to determine the potential of the test chemical to cause eye irritation assessed in rabbits. 5% formulation of the test chemical was instilled into rabbit eyes and observed for effects (duration, observation period not specified). No signs of irritation were observed when rabbits were exposed to the test chemical. Hence, the test chemical was considered to be not irritating to eyes.

 

Based on the available in-vivo data, it can be concluded that the given test chemical cannot cause irritation to rodent’s eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for eye irritation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation:

In different studies, the given test chemical has been investigated for the dermal irritation potential to a greater or lesser extent. The studies are based on in-vitro and in-vivo experiments conducted in rodents which have been summarized as below -

 

The dermal irritation potential of test article was determined according to the OECD 439 test guideline for this study. The MatTek EpiDerm™ model was used to assess the potential dermal irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to the test article and controls for ~one hour, followed by a 42 hour post-exposure recovery period. The viability of each tissue was determined by MTT assay.  The MTT data show the assay quality controls were met and passed the acceptance of criteria. The Mean % tissue viability compared to negative control (n=3) of the test substance was determined to be 95.1%. Hence, under the current experimental test conditions it was concluded that test substance was considered to be not irritating to human skin and can thus be classified as “Not Classified'' as per CLP Regulation.

 

The above in-vitro study is supported with the study designed and conducted to determine the dermal reaction profile of the given test chemical in Sprague Dawley rats. The study was performed as per OECD Guidelines 402 and complying to the GLP procedures. Ten rats (5 male and 5 female) were used for conducting dermal irritation /corrosion study. The animals were kept in their cages for at least 5 days prior to administration for acclimatization to the laboratory condition and after acclimatization period, animals were randomly selected. Approximately 24 hours before application, the hair of each rat was closely clipped from the trunk (dorsal surface and sides from scapular to pelvic area) with an electric clipper, so as to expose at least 10% of the body surface area. The test item was moistened with distilled water. The test item was applied onto the exposed skin of the animal, taking care to spread the test item evenly over the entire area of approximately 10% of the total body surface area or as much of the area as can reasonably be covered. The test item was held in contact with the skin using a porous gauze dressing and non-irritating tape around the animal to cover the exposure site for first 24 hours exposure period. Elizabethan collar was placed on each animal for first 24 hours after application of the test item. These collars prevent ingestion of test item. Following 24 hours of exposure, the wrapping was removed and the test site wiped free of excess test item. Distilled water was used to remove residual test item. The test item was applied to shorn skin of 5 male and 5 female animals at 2000 mg/kg body weight. Administration of the test item at 2000 mg/kg did not result in any skin reaction at the site of application during the study period of 14 days. Administration of the test item did not result in any signs of toxicity and mortality during the study period of 14 days. Animals exhibited normal body weight gain through the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment. The overall irritation score of the substance was determined to be 0 and no erythema and edema (skin irritation) were found at the end of 14 days observation period after patch removal. Hence, it was concluded that the given test chemical was Non-Irritating to the skin of Sprague Dawley rats under the experimental conditions tested and cannot be classified as per CLP Classification.

 

Both the above studies are further supported with another study designed and conducted to determine the dermal reaction profile of the test chemical in Sprague Dawley rats. The study was performed as per OECD Guidelines 402 and complying to the GLP procedures. Ten rats (5 male and 5 female) were used for conducting dermal irritation /corrosion study. The animals were kept in their cages for at least 5 days prior to administration for acclimatization to the laboratory condition and after acclimatization period, animals were randomly selected. Approximately 24 hours before application, the hair of each rat was closely clipped from the trunk (dorsal surface and sides from scapular to pelvic area) with an electric clipper, so as to expose at least 10% of the body surface area. A single dose of 2000 mg of the test item per kilogram of body weight was administered to ten rats (five males and five females). The test item was applied directly onto the exposed skin of the animal, taking care to spread the test item evenly over the entire area of approximately 10% of the total body surface area or as much of the area as can reasonably be covered. The test item was held in contact with the skin using a porous gauze. Dressing and non-irritating tape around the animal to cover the exposure site for first 24 hours exposure period. Elizabethan collar was placed on each animal for first 24 hours after application of the test item. These collars prevent ingestion of test item. Following 24 hours of exposure, the wrapping was removed and the test site wiped free of excess test item. Distilled water was used to remove residual test item. The overall irritation score of the substance was determined to be 0 and no erythema and edema (skin irritation) were found at the end of 14 days observation period after patch removal. Hence, it was concluded that the test chemical was Non-Irritating to the skin of Sprague Dawley rats under the experimental conditions tested and cannot be classified as per CLP Classification.

 

Based on the available in-vitro and in-vivo data for the test chemical, it can be concluded that the test chemical was considered to be not irritating to skin. Thus it cannot be classified for skin irritation.

 

Eye irritation:

The ocular irritation potential was assessed based on the available results from the in-vivo studies for the given test chemical.These studies have been summarized as below -

 

The local eye irritative potential of test chemical was investigated in rabbits’ eye to assess the degree of eye irritancy caused by the chemical. Each rabbit received 2 installation of 0.2 ml of a 10% test chemical aqueous suspension into the conjunctival sac of rabbits 5 times per week for 4 weeks. The chemical produced only minimal irritating effects after 2 hours which could not confirmed the irritation potential. Hence, on the basis of findings the Test chemical can be considered as not irritating to the rabbits’ eye.

 

The above study is supported with another eye irritation study conducted to determine the potential of the test chemical to cause eye irritation assessed in rabbits. 5% formulation of the test chemical was instilled into rabbit eyes and observed for effects (duration, observation period not specified). No signs of irritation were observed when rabbits were exposed to the test chemical. Hence, the test chemical was considered to be not irritating to eyes.

 

Based on the available in-vivo data, it can be concluded that the given test chemical cannot cause irritation to rodent’s eyes. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for eye irritation.

 

Justification for classification or non-classification

Based on the available in-vitro and in-vivo data for the test chemical, it can be concluded that the test chemical was considered to be not irritating to skin and eyes. Thus it cannot be classified for skin and eye irritation.