Diphenyl sulphide

Endpoint summary

Description of key information

Skin irritation

The dermal irritation potential of target chemical was assessedin various experimental studies which were conducted on rabbits for target chemical and its structurally similar read across substances.Based on the available data for the target and read across substances and applying the weight of evidence approach, it can be concluded that chemical is able to cause skin irritation and thus considered as irritating. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category- 2: Irritant”.

 

Eye irritation

An ocular irritation potential of target chemical Diphenyl sulphide (CAS No. 139 -66 -2) was assessedin various experimental studies which were conducted on rabbits for target chemicalDiphenyl sulphide (CAS No. 139 -66 -2) and its structurally similar read across substancesDiphenyl ether (CAS no:101-84-8) and Biphenyl (CAS no: 92-52-4).Based on the available data for the target and read across substances and applying the weight of evidence approach, it can be concluded that chemical Diphenyl sulphide (CAS No. 139 -66 -2) is unable to cause eye damage and thus can be considered as not irritating. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Data is from peer-reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

The primary skin irritation study was conducted for Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) on albino rabbits.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Phenyl sulfide
- Molecular formula: C12H10S
- Molecular weight: 186.277 g/mole
- Substance type: Organic
- Physical state: Liquid

Species:

rabbit

Strain:

other: Albino New Zealand

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data available
- Age at study initiation: No data available
- Weight at study initiation: 2.5 to 3.5 kg
- Fasting period before study: No data available
- Housing: No data available
- Diet (e.g. ad libitum): No data available
- Water (e.g. ad libitum): No data available
- Acclimation period: No data available
- Sex: Male

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%):No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): No data available

IN-LIFE DATES: From: To: No data available

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

other: Undiluted sample or of solutions in water, propylene glycol, or acetone

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):0.01 mL

Duration of treatment / exposure:

24-hours

Observation period:

24-hours

Number of animals:

5

Details on study design:

TEST SITE
- Area of exposure: Rabbit belly
- % coverage: No data available
- Type of wrap if used: No data available

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No data available
- Time after start of exposure: Exposed for 24-hour

SCORING SYSTEM:
A 10-grade ordinal series and is based upon the severest reaction that develops on the clipped skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. Grade 1 indicates no irritation and Grade 2 the least visible capillary injection from the undiluted chemical. Grade 6 indicates necrosis when undiluted and Grade 10 indicates necrosis from a 0.01% solution.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24 h

Score:

5

Max. score:

10

Reversibility:

no data

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The primary skin irritation study was conducted for Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) on albino rabbits. A score of 5 was recorded. Hence, it was concluded that Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) was irritating to the skin of albino rabbits under the experimental conditions tested and classified as “Category- 2: Irritant” as per CLP criteria.

Executive summary:

The primary skin irritation study was conducted for Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) on albino rabbits. The test item phenyl sulfide was applied on the clipped skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. A score of 5 was recorded. Hence, it was concluded that Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) was irritating to the skin of albino rabbits under the experimental conditions tested and classified as “Category- 2: Irritant” as per CLP criteria.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Data is from peer-reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

The study was conducted to evaluate the acute eye irritation potential of Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) in albino rabbits.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Phenyl sulfide
- Molecular formula: C12H10S
- Molecular weight: 186.277 g/mole
- Substance type: Organic
- Physical state: Liquid

Species:

rabbit

Strain:

other: Albino New Zealand

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.5 to 3.5 kg
- Sex: Male

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): undiluted chemical

VEHICLE (not used)
- Amount(s) applied (volume or weight with unit): No data
- Concentration (if solution): No data
- Lot/batch no. (if required): No data
- Purity: No data

Duration of treatment / exposure:

No data available

Observation period (in vivo):

No data available

Number of animals or in vitro replicates:

No data available

Details on study design:

TEST SITE
- Area of exposure: Eye
- % coverage: No data available
- Type of wrap if used: No data available

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No data available
- Time after start of exposure: No data available

SCORING SYSTEM:
A 10- grade ordinal series and is based upon the degree of corneal necrosis that results from instillation of various volumes and concentrations of chemical. Grade 1 indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Grade 5 indicates a so-called severe burn from 0.005 ml, and Grade 10 indicates a severe burn from 0.5 ml of a 1% solution in water or propylene glycol.

Irritation parameter:

other: corneal necrosis

Basis:

mean

Score:

2

Max. score:

10

Reversibility:

not specified

Remarks on result:

probability of mild irritation

Interpretation of results:

other: Not irritating

Conclusions:

The test substance Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) was considered to be not irritating to the rabbit eyes.

Executive summary:

The study was conducted to evaluate the acute eye irritation potential of Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) in albino rabbits. A score of 2, indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Hence, it was concluded that test substance Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139 -66 -2) was considered to be not irritating to the rabbit eyes.

Reference 2

Endpoint:

eye 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 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

Principles of method if other than guideline:

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

GLP compliance:

no

Species:

human

Strain:

other: Not applicable

Details on test animals or tissues and environmental conditions:

- 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 corneal mucosa. 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 Identification
All of the EpiOcular™ 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 is included in this report. Tissue plates were appropriately labeled with study information. Bias was not a factor in this test system.

- Justification of the test method and considerations regarding applicability
EpiOcularTM Eye Irritation (OCL) by MatTek In Vitro Life Science Laboratories, Bratislava, Slovakien.
The test articles and controls were evaluated for potential ocular irritancy using the EpiOcular™ 3 dimensional human tissue model purchased from MatTek In Vitro Life Science Laboratories, Bratislava, Slovakien.
The EpiOcular tissue construct is a nonkeratinized epithelium prepared from normal human keratinocytes (MatTek). It models the cornea epithelium with progressively stratified, but not cornified cells. These cells are not transformed or transfected with genes to induce an extended life span in culture. The “tissue” is prepared in inserts with a porous membrane through which the nutrients pass to the cells. A cell suspension is seeded into the insert in specialized medium. After an initial period of submerged culture, the medium is removed from the top of the tissue so that the epithelial surface is in direct contact with the air. This allows the test material to be directly applied to the epithelial surface in a fashion similar to how the corneal epithelium would be exposed in vivo. Each lot of tissues was Quality Assured by MatTek In Vitro Life Science Laboratories according to specific QC standards including: histology (cell layers), tissue viability (MTT mean optical density) and reproducibility (SD)

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 μL of liquid test article
- Concentration (if solution): neat (undiluted)

VEHICLE (no vehicle)
- 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): 50 μL
- Concentration (if solution): neat

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): neat

Duration of treatment / exposure:

Tissues were exposed for approximately 30 minutes for liquid test article and controls, at approximately 37°C, 5% CO2 in a humidified incubator.

Observation period (in vivo):

Not applicable

Duration of post- treatment incubation (in vitro):

Following the washing step and the post-soak, the tissues were incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of ~2 hours for liquid test articles , or 18 hrs for solid test articles, and controls.

Number of animals or in vitro replicates:

2 tissues were used for test compound and control.

Details on study design:

- Details of the test procedure used
The tissues were exposed to the test article neat (undiluted). EpiOcular™ 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 30 minutes for liquid test articles and controls, at approximately 37°C, 5% CO2 in a humidified incubator. After the exposure, the test article was rinsed off the tissues and the tissues were soaked in media for ~12 minutes for liquid test articles and controls. Following the washing step and the post-soak, the tissues were incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of ~2 hours for liquid test articles and controls. Tissue viability was assessed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

- MTT Auto reduction and colouring assessment
MTT Pre-test
The test article was assessed for the potential to interfere with the assay. Approximately 50 µL of liquid test article was added to 1 mL of MTT media (~1 mg/mL) and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 3 hours. 50 µL of ultrapure water was used as a negative control.

- Test Article Color Test
Approximately 50 µL of liquid test article was added to 1.0 mL of ultrapure water and 2.0 mL isopropanol and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 2 hours, 04 minutes and 35 seconds. Samples were then added to the wells of a clear 96-well plate and the plate was read on a Thermo Scientific Multiskan FC Microplate Photometer to 570 nm. Test articles that tested positive for excessive coloration (OD >0.08) were assessed on living-tissue controls that were incubated in both culture media and MTT media as well (n=3 for both conditions).

- MTT Assay:
After the recovery period, the MTT assay was performed on run 1 tissues by transferring the tissues to 24-well plates containing 300 µL MTT medium (1.0 mg/mL). After 3 hours of 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 for liquid exposed tissues was overnight incubation. 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 was 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 EpiOcular™ tissue cultures were placed in 1.0 mL of fresh Maintenance medium (in a 6-well plate) for 60 minutes. After the 60 minutes incubation, the Maintenance medium was exchanged with fresh medium and the tissues were incubated overnight (16-24 hrs) at approximately 37°C, approximately 5% CO2 in a humidified incubator.
2. Control and Test Article Exposures:
20 µL of calcium and magnesium free DPBS was added to each tissue and the tissues placed back into the incubator for 30 minutes. The controls and the test article will be applied topically to tissues by pipette. Three tissues will be used per test compound and control.
a)Controls: 50 µL of negative control sterile ultrapure water and positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
b)Test Article: 50 µL of liquid test article were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
3. Post exposure treatment:
After the exposure, the tissues were rinsed 20 times with sterile DPBS to remove test material. The apical surface was gently blotted with a cotton swab and cultures were immediately transferred to a 12-well plate containing 5 mL of media per well. Tissues exposed to liquid test articles (and the respective control) were incubated, submerged in the media for ~12 minutes at room temperature.For liquid test articles, tissues, Tissuses were then transferred to 6-well plates containing 1.0 mL fresh Maintenance medium per well and incubated for a post-exposure recovery period for 2 hours at approximately 37 degC, 5% CO2 in a humidified incubator.
- Doses of test chemical and control substances used
Test Article:
50 µL of liquid test article were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
Controls: 50 µL of negative control sterile ultrapure water, positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
- Duration and temperature of exposure, post-exposure immersion and post-exposure incubation periods: Tissues were exposed for approximately 30 minutes for liquid test articles and controls, at approximately 37°C, 5% CO2 in a humidified incubator. Following the washing step and the, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time totaling ~2 hours for liquid test articles and controls.
- Justification for the use of a different negative control than ultrapure H2O (Not applicable
- Justification for the use of a different positive control than neat methyl acetate (Not applicable)
- Number of tissue replicates used per test chemical and controls: 2 tissues were used for test compound and control.
- Description of the method used to quantify MTT formazan
The blue formazan salt was extracted by submerging tissues in 2 mL isopropanol in a 24-well plate. The extraction for liquid exposed tissues was overnight incubation with a 20 minute 24 second shake the following morning. 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. The blue formazan salt was extracted by placing the tissue insterts in 1 mL isopropanol in a 6-well plate. The extraction for solid exposed tissues was 3 hrs incubation. After an addition of 1 ml isopropanol and mixing, the optical density of the extracted formazan (200μL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm.

- Description of evaluation criteria used including the justification for the selection of the cut-off point for the prediction model
Calculations and Statistical Methods
MTT Assay
Blanks:
· The 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.
ODblank= optical density of blank samples (isopropanol alone).
ODNCraw= optical density negative control samples.
ODNC= optical density of negative control samples after background subtraction.
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.
ODPCraw= optical density positive control samples.
ODPC= optical density of positive control samples after background subtraction.
Tested Articles:
· Calculate the blank corrected value ODTT= ODTTraw– ODblank.
· The OD mean per tissue is calculated.
· The viability per tissue is calculated: %TT = [ODTT/ mean ODNC] x 100.
· The mean viability for all tissues is calculated: Mean TT = Σ %TT / number of tissues.
· The standard deviation (SD) and the percent coefficient of variation (% CV)for the controls and the test articles will be calculated.
ODTTraw= optical density test article samples.
ODPC= optical density of test article samples after background subtraction.
Data Correction Procedure for MTT Interfering Compounds
True viability = Viability of treated tissue – Interference from test article = ODtvt – ODkt where ODkt = (mean ODtkt – mean ODukt).
ODtvt = optical density of treated viable tissue
ODkt = optical density of killed tissues
ODtkt = optical density of treated killed tissue
ODukt = optical density of untreated killed tissue (NC treated tissue)

Data Correction Procedure for Colored Compounds
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 media
ODvt = optical density of viable tissues incubated in media alone.
Proposed Statistical methods
The mean, standard deviation (SD) and the percent coefficient of variation (% CV) for the controls and the test article will be calculated.
- Evaluation of data
The results of the assay was evaluated and compared to negative control.
Table: Irritancy Prediction
In VitroResults In VivoPrediction
Mean tissue viability ≤60% Irritant (I) – Category 1 or 2
Mean tissue viability >60% Non-irritant (NI) – No Category
- Assay quality controls
- Negative Controls (NC)
The assay is meeting the acceptance criterion if the mean viability of the NC in terms of Optical Density (OD570) of the NC tissues (treated with sterile ultrapure water) in the MTT assay are >0.8 to <2.5. This is an indicator of tissue viability following shipping and conditions under use.
- Positive Controls (PC)
Methyl acetate was used as a PC and tested concurrently with the test article. The assay is meeting the acceptance criteria if the viability of the PC is <50% of the negative control.
- Standard Deviation (SD)Each test of ocular irritancy potential is predicted from the mean viability determined on 3 single tissues. The assay meets the acceptance criteria if SD calculated from individual percent tissue viabilities of the replicates is <18% for three replicate tissues.

Irritation parameter:

other: mean % tissue viability

Run / experiment:

Run 1

Value:

100.2

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

Negative irritation

Other effects / acceptance of results:

The MTT data show the assay quality controls were met.

Table:

	Mean of OD	Diff of OD	viabilities [%]	Mean of viabilities	Diff/2	Classification
NC	2.937	0.196	100.0	6.68	3.34	NI	qualified
PC	0.926	0.017	31.5	0.59	0.30	I	qualified
139-66-2	2.943	0.133	100.2	4.53	2.27	NI	qualified

 

Code N°	Tissue	Raw data		Blank corrected data		mean of OD	% of viability
	n	Aliq. 1	Aliq. 2	Aliq. 1	Aliq. 2
NC	1	3.1865	2.9581	3.150	2.921	3.035	103.3
	2	2.815	2.9373	2.778	2.900	2.839	96.7
PC	1	0.9553	0.9523	0.918	0.915	0.917	31.2
	2	0.9687	0.9737	0.932	0.937	0.934	31.8
139-66-2	1	2.9735	2.8535	2.937	2.817	2.877	97.9
	2	3.0705	3.0229	3.034	2.986	3.010	102.5

 

Interpretation of results:

other: not irritating

Conclusions:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The mean % tissue viability of test substance Phenyl Sulfide (CAS No. 139-66-2) was determined to be 100.2%. Thus, substance Phenyl Sulfide (CAS No. 139-66-2) was considered to be not irritating to the human eyes.

Executive summary:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to liquid test articles and controls for ~30 minutes, followed by a ~12 minute post-soak and approximately 2 hour recovery after the post-soak. The viability of each tissue was determined by MTT assay.

The MTT data show the assay quality controls were met, passing the acceptance criteria.

The mean % tissue viability of test substance Phenyl Sulfide (CAS No. 139-66-2) was determined to be 100.2%. Hence, under the experimental test conditions it was concluded that test substance Phenyl Sulfide (CAS No. 139-66-2) was considered to be not irritating to the human eyes and can thus be classified as “Not classified’’ as per CLP Regulation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation:

Various studieshas been investigated for the test chemical  to observe the potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo and in vitro experiments in rabbits for target chemical and its structurally similar read across substances which have beensummarized as below;

 

The HENRY F. SMYTH et.al, {American Industrial Hygiene Association Journal, V.23:2, pages 95-107 1962} conducted primary skin irritation study for target chemical Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) on albino rabbits. The test item phenyl sulfide was applied on the clipped skin of each of five albino rabbits within 24 hours of the uncovered application of 0.01 ml of undiluted sample or of solutions in water, propylene glycol, or acetone. A score of 5 was recorded. Hence, it was concluded that Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) was irritating to the skin of albino rabbits under the experimental conditions tested and classified as per CLP criteria.

 

The MAK Collection for Occupational Health and Safety {Diphenylether (steam) [MAK Value Documentation in German language, 2004] The MAK Collection for Occupational Health and Safety. 1–11. 2012} carried out the skin irritation study for read across chemical Diphenyl ether (CAS no:101-84-8) on six New Zealand rabbits.When 0.5 ml of diphenyl ether was applied to the skin of six New Zealand rabbits, erythema and edema was observed, which was rated at stimulus strength of 5.5 on a scale of a maximum of 8 points.Hence the chemicalDiphenyl ether (CAS no:101-84-8) was considered to be irritating to the skin of six New Zealand rabbits.

 

The above results were further supported by the experimental study reported by NTRL (National Technical Reports Library) {NTRL (National Technical Reports Library); OTS0546109; 28 August 1992} on New Zealand white male and female rabbits for read across substance Biphenyl (CAS no: 92-52-4). Approximately 500 mg of finely ground Biphenyl was applied onto the intact and clipped skin of each rabbit moistened with water under a one inch by one inch square patch, two single layers thick. The patches were held in place with adhesive tape. The trunk of each animal was wrapped with plastic strip, to retard evaporation and avoid contamination, for the twenty-four hour exposure period. Observations were made over a period of seven days for irritation. The skin reactions were observed over a period of seven days according to the method of Draize, Woodard, and Calvery (Journal  of Pharm. and Exp. Therapeutics, Volume 82, December, 1944). The average maximum score was observed to be 6 out of a possible 8 in one twenty four hours. Therefore, the chemical Biphenyl (CAS no: 92-52-4) was considered to be severely irritating to the skin of New Zealand white rabbits.

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 of OD for test chemical was determined to be 1.574. The standard deviation of viabilities for test chemical were calculated to be 0.096.The Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 69.9%.Hence, under the current experimental test conditions it was concluded that test chemical was considered to be not irritating to human skin.

 

Thus on the basis of available data for thetarget chemical  and its structurally similar read across substances,it can be concluded thatchemical Diphenyl sulphide (CAS No. 139 -66 -2)  is able to cause skin irritation and considered as irritating. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category- 2: Irritant”.

 

Eye irritation:

In different studies,the test chemicalDiphenyl sulphide (CAS No. 139 -66 -2)  has been investigated for potential for ocular irritationto a greater or lesser extent. The studies are based on in vivo experiments in rabbits for target chemicalDiphenyl sulphide (CAS No. 139 -66 -2) andits structurally similar read across substancesDiphenyl ether (CAS no:101-84-8) and Biphenyl (CAS no: 92-52-4) that have beensummarized as below;

 

The HENRY F. SMYTH et.al., {American Industrial Hygiene Association Journal, V.23:2, pages 95-107 1962} conducted acute eye irritation study of Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139-66-2) in albino rabbits. A score of 2, indicates at most a very small area of necrosis resulting from 0.5 ml of undiluted chemical in the eye. Hence, it was concluded that test substance Diphenyl sulphide/ Phenyl Sulfide (CAS No. 139 -66 -2) was considered to be not irritating to the rabbit eyes.

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to liquid test articles and controls for ~30 minutes, followed by a ~12 minute post-soak and approximately 2 hour recovery after the post-soak. The viability of each tissue was determined by MTT assay.

The MTT data show the assay quality controls were met, passing the acceptance criteria.

The mean % tissue viability of test substance Phenyl Sulfide (CAS No. 139-66-2) was determined to be 100.2%. Hence, under the experimental test conditions it was concluded that test substance Phenyl Sulfide (CAS No. 139-66-2) was considered to be not irritating to the human eyes and can thus be classified as “Not classified’’ as per CLP Regulation

 

The MAK Collection for Occupational Health and Safety {Diphenylether (steam) [MAK Value Documentation in German language, 2004] The MAK Collection for Occupational Health and Safety. 1–11. 2012} carried out an ocular irritation study for read across chemical Diphenyl ether (CAS no:101-84-8) for chemical Diphenyl ether (CAS no:101-84-8) on six New Zealand rabbits.When 100µl of diphenyl ether was instilled into the conjunctival sac of six New Zealand rabbits, redness was observed, which was observed after 24 hours and slight conjunctival irritation, which completely disappeared after 72 hours.Since the observed effects were not persisted, the chemicalDiphenyl ether (CAS no:101-84-8) was considered to be not irritating to the eyes of six New Zealand rabbits.

 

The above results were further supported by the experimental study reported by EUROPEAN COMMISSION – European Chemicals Bureau {IUCLID Dataset;EUROPEAN COMMISSION – European Chemicals Bureau;19–FEB–2000} for read across chemical Biphenyl (CAS no: 92-52-4). Approximately 10 mg of Biphenyl was placed into the eyes of each rabbit that resulted into slight conjunctival irritation, which appeared 24 h after the instillation of the test substance. Therefore, the chemical Biphenyl (CAS no: 92-52-4) was considered to be not irritating to the rabbits’ eye.

 

The in vivo and in vitro data are in mutual agreement with each other indicating a strong possibility of the test chemical being not irritating to skin. Hence, the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of the CLP regulation the test chemical can be classified under the category “Not Classified”. 

Justification for classification or non-classification

The skin and eye irritation potential of test chemical Diphenyl sulphide (CAS No. 139 -66 -2)  and its structurally similar read across substances were observed in various studies. The results obtained from these studies indicate that the chemical Diphenyl sulphide (CAS No. 139 -66 -2) is able to cause skin irritation but unlikely to cause eye irritation. Hence Diphenyl sulphide (CAS No. 139 -66 -2)  can be classified under the category “Category- 2: Irritant” for skin and “Not Classified” for eye as per CLP.