12-hydroxy-N-(2-hydroxyethyl)octadecan-1-amide

Endpoint summary

Description of key information

Skin Irritation

The results from these experimental studies lead to a possibility of the test chemical being not irritating to skin. By applying the weight of evidence approach, the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Eye irritation

The ocular irritation potential of target chemical was assessedin various in- vitro and in-vivo experimental studies.Based on the available key data and supporting studies,it can be concluded that the testchemical is unable to cause eye irritation and 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:

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:

Weight of evidence approach based on various test chemicals

Justification for type of information:

Weight of evidence approach based on various test chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Weight of evidence approach based on various test chemicals

Principles of method if other than guideline:

Weight of evidence approach based on various test chemicals. The study 2,3,4 are referred as study 1,2,3

GLP compliance:

not specified

Species:

other: 1. rat; 2,3. rabbits

Strain:

not specified

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

other: 1,3. undiluted; 2. propylene glycol at a 9 to 1 dilution

Controls:

not specified

Amount / concentration applied:

1. 200,100, 2000 mg/kg body weight
2. 10% concentration in propylene glycol at a 9 to 1 dilution
3. 0.5 ml undiluted

Duration of treatment / exposure:

1. 24 hours
2. 5 days per week for 2 weeks
3. not specified

Observation period:

1. 14 days
2. 14 days
3. 24, 48 and 72 hours

Number of animals:

1. 5 female rats
2. colonies of rabbits
3. 6 rabbits

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

14 d

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Interpretation of results:

other: not irritating

Conclusions:

The results from these experimental studies lead to a possibility of the test chemical being not irritating to skin. By applying the weight of evidence approach, the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Executive summary:

Various studies have been summarized to determine the extent of dermal irritation caused by the test chemical in living organisms. These results include in vivo experimental studies performed on rabbits, rats for the various test chemicals.

A study was 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. 5 female nulliparous and non-pregnant Sprague Dawley rats were used for the study.

In the dose range finding study a single dose of 200 mg/kg body weight of the test item was administered to 1 female animal. No death or clinical signs of toxicity was observed during first 48 hours, hence, additional 1 female animal was administered with the dose of 1000 mg/kg body weight. Administration of 1000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours, hence, additional 1 female animal was administered at the dose of 2000 mg/kg body weight. Administration of 2000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours.

As the dose range finding study revealed no mortality or clinical signs at the maximum dose of 2000 mg/kg, the main study was initiated with two additional animals. The animals were administered with a dose of 2000 mg/kg body weight in sequential manner at 48 hours intervals.

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 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. 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 classified as “Category- Not Classified” as per CLP Classification.

This is supported by the results of a study performed on a rabbit ear to indicate the Comedogenicity and irritancy of the test chemical. The test chemical was mixed in propylene glycol at a 9 to 1 dilution for testing unless otherwise indicated (10% concentration). Colonies of New Zealand albino rabbits that have genetically good ears and free from mites were used. Three rabbits, weighing two to three kilograms, were used for each assay. Animals were housed singly in suspended cages and fed Purina Rabbit Chow and water ad libitum. Animals were maintained on a 12-hour light and 12-hour dark cycle. A dose of 1 ml of the test material was applied and spread once daily to the entire inner surface of once for five days per week for two weeks. The opposite untreated ear of each animal served as an untreated control.

The irritancy produced by repeated application of the chemical on the surface epidermis in the rabbit ear is evaluated on a scale of 0 to 5. The grades are summarized as follows:

 0 = No irritation; 1 = few scales, no Erythema; 2 = diffuse scaling, no Erythema; 3 = Generalized scaling with Erythema; 4 = Scaling, Erythema and Edema; 5 = Epidermal necrosis and slough.

The test chemical falls under Grade 0 (no irritation observed).

Hence it can be concluded that the test chemical was not irritating to rabbit ears.

The above results are supported by a study performed to assess the skin irritation potential of the test chemical in rabbits. The test was performed according to the procedure outlined in the Journal Officiel de la Republique Francaise.

0.5 ml undiluted test chemical was applied under occlusion to the clipped skin of 6 albino rabbits. The reactions were scored at 24, 48 and 72 hours.

The Primary Irritation Index of undiluted test chemical was 0.0. Hence, the test chemical can be considered not irritating to rabbit skin.

The results from these experimental studies lead to a possibility of the test chemical being not irritating to skin. By applying the weight of evidence approach, the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

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 in the (MTT) assay, in the MatTek EpiOcular™ model

GLP compliance:

no

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (Not applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature / Fridge storage
- Stability under test conditions: No data available
- Solubility and stability of the test substance in the solvent/vehicle: No data available
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No data available

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test article tested as provided neat (undiluted).
- Preliminary purification step (if any): No data available
- Final dilution of a dissolved solid, stock liquid or gel: No data available
- Final preparation of a solid: No data available

FORM AS APPLIED IN THE TEST:solid

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 Lab. (Bratislava, Slovakia).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, Inc. 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 mg of solid test chemical
- 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 6 hrs ± 15 min for solid test articles, 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 and post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of 18 hours for solid test chemicals 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 6 hrs ± 15 min for solid 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 ~25 minutes for solid test articles and controls.Following the washing and post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of 18 hours for solid test chemicals 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:
Inserts are removed from the 24-well plate after 3 hrs of incubation and the bottom of the insert is blotted on absorbent material, and then transferred to a pre-labeled 6-well plate containing 1 ml isopropanol in each well so that no isopropanol is flowing into the insert. At the end of the non-submerged extraction inserts and tissues are discarded without piercing and 1 ml of isopropanol is added into each well. The extract solution is mixed and the optical density of the extracted formazan (200 μL/well of a 96-well plate) was determined using 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.2 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: When a solid was tested, 50 mg of the solid were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 6 hrs ± 15 min.
3. Post exposure treatment:
After the exposure, the tissues were rinsed 20 times with sterile of 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:
When a solid was tested, 6 hours of the solid were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 6 hrs ± 15 min.
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 6 hours for solid test articles and controls, at approximately37°C, 5% CO2 in a humidified incubator.
Following the post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time totaling 18 hours for solid 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 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 meanthe 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 2 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:

102.1

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Remarks:

Mean O.D. =102.1 , SD= 4.69 , CV= 2.35 ;Not Irritant

Other effects / acceptance of results:

The MTT data show the assay quality controls were met.

 Observation table:

Code N°	Tissue	Raw data		Blank corrected data		mean of OD	% of viability
	n	Aliq. 1	Aliq. 2	Aliq. 1	Aliq. 2
NC	1	1.6752	1.7124	1.640	1.678	1.659	91.1
	2	2.0433	1.9913	2.009	1.957	1.983	108.9
PC	1	0.5161	0.5323	0.481	0.498	0.489	26.9
	2	0.5283	0.5278	0.494	0.493	0.493	27.1
Test chemical	1	1.8604	1.8407	1.826	1.806	1.816	99.7
	2	1.9233	1.9486	1.889	1.914	1.901	104.4

 

 

	mean	Dif.	mean of	Dif.	Dif./2	Classification
	of OD	of OD	viabilities [%]	of viabilities
NC	1.821	0.324	100.0	17.77	8.88	NI	qualified
PC	0.491	0.004	27.0	0.21	0.11	I	qualified
Test chemical	1.858	0.085	102.1	4.69	2.35	NI	qualified

 

Where,

NC= Negative control

PC= Positive control

TC= Test chemical

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 was determined to be 102.1%. Thus, the test chemical 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 solid test articles and control for approx.6 hours, followed by a 25 minute post-soak and approximately 18 hours 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 was determined to be 102.1%. Hence, under the experimental test conditions it was concluded that test substance 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 studies have been summarized to determine the extent of dermal irritation caused by the test chemical in living organisms. These results include in vivo experimental studies performed on rabbits, rats for the various test chemicals.

A study was 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. 5 female nulliparous and non-pregnant Sprague Dawley rats were used for the study.

In the dose range finding study a single dose of 200 mg/kg body weight of the test item was administered to 1 female animal. No death or clinical signs of toxicity was observed during first 48 hours, hence, additional 1 female animal was administered with the dose of 1000 mg/kg body weight. Administration of 1000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours, hence, additional 1 female animal was administered at the dose of 2000 mg/kg body weight. Administration of 2000 mg/kg body weight did not reveal any clinical signs of toxicity or death during first 48 hours.

As the dose range finding study revealed no mortality or clinical signs at the maximum dose of 2000 mg/kg, the main study was initiated with two additional animals. The animals were administered with a dose of 2000 mg/kg body weight in sequential manner at 48 hours intervals.

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 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. 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 classified as “Category- Not Classified” as per CLP Classification.

This is supported by the results of a study performed on a rabbit ear to indicate the Comedogenicity and irritancy of the test chemical. The test chemical was mixed in propylene glycol at a 9 to 1 dilution for testing unless otherwise indicated (10% concentration). Colonies of New Zealand albino rabbits that have genetically good ears and free from mites were used. Three rabbits, weighing two to three kilograms, were used for each assay. Animals were housed singly in suspended cages and fed Purina Rabbit Chow and water ad libitum. Animals were maintained on a 12-hour light and 12-hour dark cycle. A dose of 1 ml of the test material was applied and spread once daily to the entire inner surface of once for five days per week for two weeks. The opposite untreated ear of each animal served as an untreated control.

The irritancy produced by repeated application of the chemical on the surface epidermis in the rabbit ear is evaluated on a scale of 0 to 5. The grades are summarized as follows:

 0 = No irritation; 1 = few scales, no Erythema; 2 = diffuse scaling, no Erythema; 3 = Generalized scaling with Erythema; 4 = Scaling, Erythema and Edema; 5 = Epidermal necrosis and slough.

The test chemical falls under Grade 0 (no irritation observed).

Hence it can be concluded that the test chemical was not irritating to rabbit ears.

The above results are supported by a study performed to assess the skin irritation potential of the test chemical in rabbits. The test was performed according to the procedure outlined in the Journal Officiel de la Republique Francaise.

0.5 ml undiluted test chemical was applied under occlusion to the clipped skin of 6 albino rabbits. The reactions were scored at 24, 48 and 72 hours.

The Primary Irritation Index of undiluted test chemical was 0.0. Hence, the test chemical can be considered not irritating to rabbit skin.

The dermal irritation potential of test article was determined according to the OECD 439 test guideline followed 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. The objective of this study was to assess the dermal irritation potential of test article Tissues were exposed to 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 Mean % tissue viability compared to negative control (n=3) of the test substance was determined to be 90.6%. Hence, under the experimental test conditions it was concluded that test substance was considered to be not irritating to the human skin and being classified as “Not Classified'' as per CLP Regulation.

The results from these experimental studies lead to a possibility of the test chemical being not irritating to skin. By applying the weight of evidence approach, the test chemical can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical can be classified under the category “Not Classified”.

Eye Irritation

Various studieshave been investigated for the test chemical to observe the potential for ocular irritation to a greater or lesser extent. The studies are based on in-vitro and in-vivo experiments conducted for target chemicaland its structurally similar read across substanceswhich have beensummarized as below;

 

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 solid test articles and control for approx.6 hours, followed by a 25 minute post-soak and approximately 18 hours 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 was determined to be 102.1%. Hence, under the experimental test conditions it was concluded that test substance was considered to be not irritating to the human eyes.

 

The above in-vitro study was supported by in-vivo experimental studies carried out on rabbits to assess the irritation potency of the structurally similar read across chemical. 0.1 ml dose of the test chemical was placed into the conjunctival sac of one eye of 6 New Zealand White rabbits. The contralateral eye of each rabbit was considered the control. Observations were recorded 1, 2, and 3 days after the introduction of the test ingredient. The reactions were graded as determined by the Consumer Product Safety Act regulations. None of the six rabbits tested had any irritation of the cornea or iris. Four rabbits had slight conjunctivitis. Three of these continued to have the condition beyond the observation period, while one rabbit had conjunctival redness only on the first day of testing. The Draize Maximum average score was calculated to be 2.3. The test chemical was considered to be not irritating to rabbit eyes.

 

The above results are supported by the experimental study for the test chemical. 0.1 ml undiluted test chemical was placed into the conjunctival sac of one eye of 6 [3 male and 3 female] New Zealand White rabbits. The treated eye received no further treatment. Observations were recorded 1, 2, and 3 days after the introduction of the test ingredient. No corneal, conjunctival, or iridial irritation was noted over a 3-day observation period. Hence, the test chemical was considered to be not irritating to rabbit eyes.

 

Thus, on the basis of results obtained in key and supportingstudies,it can be concluded that the testthe chemical is not able to cause eye irritation and considered as not irritating. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

Justification for classification or non-classification

The results of the experimental studies from the various test chemicals indicate a possibility that the test chemical can be not irritating to skin and eyes.

Hence by applying the weight of evidence approach, the test chenical can be considered to be not irritating to skin and eyes. It can be classified under the category “Not Classified” as per CLP regulation.