Isopentyl phenylacetate

Endpoint summary

Description of key information

Skin Irritation

A skin irritation study was performed in humans to assess the irritation potential of test chemical 2% in petrolatum was tested on 29 human volunteers in a 48 hours closed patch test. The volunteers were observed for signs of irritation. Since no signs of skin irritation were observed, the test chemical was considered to be not irritating to human skin after 48 hours exposure.

The dermal irritation potential of test article was also determined according to the OECD 439 In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method”. 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 Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 81.8%. Hence, under the experimental test conditions it was concluded that test chemical was considered to be not irritating to the human skin and being classified as “Not Classified'' as per CLP Regulation.

Eye Irritation:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT.The mean % tissue viability of test chemical was determined to be 95.2%. Thus, the test chemical was considered to be not irritating to MatTek EpiOcular Tisssue Model OCL-200 and being classified as “Not classified’” as per CLP Regulation.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

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:

data from handbook or collection of data

Justification for type of information:

data is from peer reviewed journaks

Qualifier:

according to guideline

Guideline:

other: as per mentioned below

Principles of method if other than guideline:

To assess the dermal irritation potential of the test chemical in humans

GLP compliance:

not specified

Species:

other: humans

Strain:

not specified

Details on test animals or test system and environmental conditions:

no data

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

other: Petrolatum

Controls:

not specified

Amount / concentration applied:

2% in petrolatum

Duration of treatment / exposure:

48 hours ,closed patch

Observation period:

48 hours

Number of animals:

29 human volunteers

Details on study design:

No data

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

48 h

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Other effects:

No data

Interpretation of results:

other: not irritating

Conclusions:

Since no signs of skin irritation were observed, the test chemical was considered to be not irritating to human skin after 48 hours exposure.

Executive summary:

A skin irritation study was performed in humans to assess the irritation potential of test chemical 2% in petrolatum was tested on 29 human volunteers in a 48 hours closed patch test. The volunteers were observed for signs of irritation. Since no signs of skin irritation were observed, the test chemical was considered to be not irritating to human skin after 48 hours exposure.

Reference 2

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 is to provide classification of dermal irritation potential of a chemical by using a three-dimensional human epidermis model, according to the OECD Test Guideline No. 439, “In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method”. The EpiDerm™ SIT allows discrimination between irritants of Category 2 and non-irritants, according to the UN Globally Harmonized System of Classification and Labeling of Chemicals (GHS).

GLP compliance:

yes

Test system:

other: MatTek EpiDerm™ Tissue Model (EPI-200-SIT) kit

Source species:

other: no data

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDerm™ 3-dimensional human tissues used in this study

Source strain:

other: Not applicable

Details on animal used as source of test system:

EpiDerm™ tissues, Lot No. 27646 Kits I and J, were received from MatTek on 12 Dec 2017, and Lot No. 27654 Kits O and P, were received from MatTek on 19 Dec 2017. See Appendix C for EpiDerm™ tissue Quality Control report. All tissues were refrigerated at 2-8°C upon receipt. Before use, the tissues were incubated (37±1°C, 5±1% CO2) with assay medium (MatTek) for a one-hour equilibration. The tissues were then moved to new wells with fresh medium for an additional overnight equilibrium, for 18±3 hours. Equilibration medium was replaced with fresh medium before dosing.

Justification for test system used:

The EpiDerm™ Skin Model closely parallels human skin, thus providing a useful in vitro means to assess dermal irritancy and toxicology

Vehicle:

unchanged (no vehicle)

Details on test system:

EpiDerm™ Tissue Samples
EpiDerm™ tissues, Lot No. 27646 Kits I and J, were received from MatTek on 12 Dec 2017, and Lot No. 27654 Kits O and P, were received from MatTek on 19 Dec 2017. See Appendix C for EpiDerm™ tissue Quality Control report. All tissues were refrigerated at 2-8°C upon receipt. Before use, the tissues were incubated (37±1°C, 5±1% CO2) with assay medium (MatTek) for a one-hour equilibration. The tissues were then moved to new wells with fresh medium for an additional overnight equilibrium, for 18±3 hours. Equilibration medium was replaced with fresh medium before dosing.

Mesh Compatibility
Five of the test articles supplied were liquids. These test articles were assessed for compatibility with
pre-cut nylon mesh supplied with the tissues. The mesh was placed on a slide and 30 μl of a liquid test articles or PBS (negative control) were applied. After 60 minutes of exposure, the mesh was checked microscopically. If no damage or other interaction was observed, indicating that the mesh was compatible with the test article, the mesh was used as a spreading aid.

Tissue Viability (MTT Reduction)
At the end of the incubation period, each EpiDerm™ tissue was rinsed with PBS and transferred to a 24-well plate containing 300 μl of MTT solution (1 mg/ml MTT in DMEM). The tissues were then returned to the incubator for a three-hour MTT incubation period. Following the MTT incubation period, each EpiDerm™ tissue was rinsed with PBS and then treated with 2.0 ml of extractant solution (isopropanol) per well for at least two hours, with shaking, at room temperature. Two aliquots of the extracted MTT formazan were measured at 540 nm using a plate reader (μQuant Plate Reader, Bio-Tek Instruments, Winooski, VT).
For several tissues, the test article had stained the tissues. Therefore, the tissues were extracted with only 1.0 ml, allowing extraction to occur only through the bottom of the insert. After the extraction period, the tissue insert was removed and discarded and 1.0 ml of extraction solution were added to each well, bringing the volume to a total of 2.0 ml.

Quality Controls
The assay meets the acceptance criteria if the mean OD540 of the negative control tissues is between 1.0 and 2.5, inclusive, and the mean viability of positive control tissues, expressed as percentage of the negative control tissues, is at least 20%. In addition, the standard deviation (SD) calculated from individual percent tissue viabilities of the three identically-treated replicates must be less than 18%.
Note: Chemicals that provide tissue viabilities in a range of 30% to 70% may provide high SD. If the high SD (above acceptance limits) is typical for the chemical and the classification of the chemical is consistent in all independent runs, MatTek recommends that this result be accepted, although it did not meet the Assay Acceptance Criterion.

Analysis of Data
See Table 1 for Experimental Data. The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate samples and expressed as percent viability for each sample using the following formula:
% viability = 100 X (OD sample/OD negative control)

Skin Irritation Prediction
According to the EU1,2 and GHS3 classification (R38 / Category 2 or no label), an irritant is predicted if the mean relative tissue viability of three individual tissues exposed to the test substance is 50% or less of the mean viability of the negative controls.

In vitro result In vivo Classification
Mean tissue viability ≤ 50% Category 2
Mean tissue viability > 50% Non-irritant (NI)


Assessment of direct MTT reduction and assessment of coloring or staining materials was not performed. Therefore, it cannot be fully assessed if the test articles interfered with MTT viability measurements.

Retention of Data
Upon signing the final report, all raw data, supporting documentation and reports are submitted to the Archivist by the Study Director. The raw data are filed at MB Research by project number. The final report is filed at MB Research by Sponsor name and MB project number.
All data generated during the conduct of this study will be archived at MB Research for at least one year from the date of the final report and optionally longer at additional cost. The Sponsor will be contacted in writing to determine final disposition of the records.
Any remaining test article will be discarded upon submission of the report.

Amendment to the Protocol
There were no amendments to the protocol. See Appendix C for the protocol in its entirety
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 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. Tissues were exposed to controls and the test articles for one hour, with ~35 minutes in a 37°C, 5% CO2 humidified incubator and the remaining 25 minutes at room temperature.

a) Controls
30 µL of negative control DPBS, 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 Article
For solid test article, the tissues were moistened with 25 μL of ultrapure water to improve contact of the tissue surface with the test article. Approximately 25 mg of each test article was evenly applied to the apical surface of each tissue (n=3). All the tissues were placed into the ~37°C incubator with 5% CO2. The exposure times were approximately 1 hour, with ~35 minutes exposure in the incubator and ~25 minutes at room temperature.

3.Post-exposure treatment
After the 1 hour exposure, the tissues were rinsed 20 to 25 times with 1 mL of 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 either 25 hours, 38 minutes and 23 seconds or for 24 hours, 10 minutes and 09 seconds (as there were numerous tissues, they had to be broken down into 2 sets to complete dosing in a timely manner). 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 17 hours, 03 minutes and 34 seconds prior to performing the MTT assay, 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: 6/08/2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37°C
- Temperature of post-treatment incubation (if applicable): 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: Twice

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 300 µL MTT medium (1.0 mg/mL).
- Incubation time: After 2 hours, 57 minute and 25 second MTT incubation
- Spectrophotometer: Synergy H4 spectrophotometer
- Wavelength: 570 nm
- Filter: No data
- Filter bandwidth: No data
- Linear OD range of spectrophotometer: No data

NUMBER OF REPLICATE TISSUES: 3

CALCULATIONS and STATISTICAL METHODS
All data were background subtracted before analysis. MTT data are presented as % viable compared to negative control. Data were generated as follows:

MTT Assay
Blanks:
·        The optical density (OD) mean from all replicates for each plate (ODblank).

Negative Controls (NC):
Identity: Phosphate-Buffered Saline (PBS), Lot No. AC10239794
Provided by:MatTek
Date Received:12 Dec 2017 and 19 Dec 2017
Expiration Date:18 Jul 2018
Storage:Room temperature and humidity
Description:Clear colorless liquid
Sample Preparation:Used as received

Positive Control (PC):
Identity: 5% Sodium Dodecyl Sulfate (SDS), Lot No. 071817MAB
Provided by:MatTek
Date Received:12 Dec 2017 and 19 Dec 2017
Expiration Date:18 Jul 2018
Storage:Room temperature and humidity
Description:Clear colorless liquid
Sample Preparation:Used as received

- 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 (undiluted)

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:

Tissues will be topically exposed to the test article and control articles for 60 minutes.

Duration of post-treatment incubation (if applicable):

After dosing, the tissues will be returned to the incubator for 35 ±1 minute, and then returned to the sterile hood for the remainder of the 60-minute exposure period.

Number of replicates:

All treatments with test articles and controls will be dosed in triplicate EpiDerm™ tissues.

Duration of treatment / exposure:

The duration of the EpiDerm™ Skin Irritation Test (SIT) is approximately five days

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Run 1

Value:

81.8

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:

All treatments with test articles and controls will be dosed in triplicate EpiDerm™ tissues.

In vitro result In vivo Classification
Mean tissue viability ≤ 50% Category 2
Mean tissue viability > 50% Non-irritant

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 chemical was determined to be 81.8%. Thus,the test chemicalwas 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 In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method”. 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 MTT data show the assay quality controls were met, as the OD of the negative control tissues was between 1.195 and 1.430. Also, the positive control, 5% sodium dodecyl sulfate (SDS), reduced tissue viability to 4.5% of negative control and the standard deviation (SD) calculated from individual percent tissue viabilities of the test article exposed replicates was passing the acceptance criteria. The Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 81.8%. Hence, under the experimental test conditions it was concluded that test chemical was considered to be not irritating to the human skin and being 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 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 is to provide classification of chemicals concerning their eye irritation potential using an alternative to the Draize Rabbit Eye Test, according to the OECD Test Guideline No. 492, “Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage”. The EpiOcular™ EIT is intended to differentiate those materials that are UN GHS No Category (i.e., do not meet the requirements for UN GHS classification) from those that would require labeling as either UN GHS Category 1 or 2. This assay is not intended to differentiate between UN GHS Category 1 / Hazard
Code 318 and UN GHS Category 2 / Hazard Codes 319 and 320.

GLP compliance:

yes

Species:

other: MatTek EpiOcular Tisssue Model OCL-200

Strain:

other: Not applicable

Details on test animals or tissues and environmental conditions:

-Test System: MatTek EpiOcular™ Tissue Model OCL-200

Storage:EpiOcular™ tissues and assay medium will be refrigerated at approximately 2-8°C upon arrival and until use.

Supplier:MatTek Corporation, Ashland, MA

- Justification of the test method and considerations regarding applicability
The EpiOcular™ Tissue Model closely parallels human ocular tissue, thus providing a useful in vitro means to assess ocular irritancy and toxicology

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

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 will be topically exposed to the test article and control articles for 30 ± 2 minutes.

Observation period (in vivo):

Not applicable

Duration of post- treatment incubation (in vitro):

Following the post soak,Tissues will be incubated in 1 ml fresh assay medium in a humidified 37±1°C, 5±1% CO2 incubator.

Number of animals or in vitro replicates:

2 tissues were used for test compound and control.

Details on study design:

-Plate Reader Linearity Check:
The linearity of the plate reader or spectrophotometer used for optical density (OD) determination will be verified prior to its use the same week the EIT assay is being
performed.
A dilution series of trypan blue or thiazolyl blue tetrazolium bromide (MTT) formazan will be prepared and 200 μl aliquots will be pipetted into a 96-well plate.
The optical density of the plate wells will be measured at a wavelength of 570 nm (OD570), with no reference wavelength.
A regression line and an R-squared value will be generated using Microsoft Excel®. Verification will be considered acceptable if the R-squared value is >0.999.

Assessment of Direct MTTReduction:No assessment of the direct MTT (methyl thiazole tetrazolium) reduction potential of each test article will be made.

-Assessment of Coloring or Staining Materials:
No assessment of each test article’s ability to absorb light at the wavelength (570 nm) used for MTT determination will be made.

- Pre-Incubation:
EpiOcular™ tissues will be placed in six-well plates containing warmed assay media and will be equilibrated in a humidified 37±1°C, 5 ±1% CO2 incubator for at least one hour. The media will then be changed and the tissues incubated overnight (16-24 hours).
Any tissues not being incubated the same day will be allowed to re-equilibrate at 37±1°C, 5±1% CO2 and will be stored at approximately 2-8°C..

-Pre-Treatment:After the overnight incubation, the tissues will be moistened with 20 μl of phosphatebuffered saline (PBS) and incubated at 37±1°C, 5±1% CO2 for 30±2 minutes.

-Dosing:50 μl of a liquid test article will be applied topically to duplicate tissues and incubated at 37±1°C, 5±1% CO2 for 30±2 minutes.
After dosing and incubation, the tissues will be thoroughly rinsed with PBS and soaked in 5 ml of room-temperature assay medium in a 12-well plate for the appropriate amount of time.
Tissues will be soaked for 12±2 minutes.

Incubation in MTT:The tissues will be incubated with 300 μl of 1 mg/ml MTT in DMEM for 3 hours ± 10 minutes at 37±1°C, 5±1% CO2

-MTT Extraction:
Following the three-hour MTT incubation period, each tissue will be removed individually and gently rinsed with PBS to remove any residual MTT solution.
The extraction plate will be covered and sealed to reduce evaporation of extractant.
For solid, colored, or staining test articles, 2.0 ml of extractant solution will be used in a six-well plate, allowing extraction to occur through the bottom of the insert.
 
Extraction Conditions:The extraction will be allowed to proceed overnight at room temperature in the dark.
Alternatively, the extraction can proceed for at least two hours, with shaking, at room temperature.

-Decant Extractant:
Tissues immersed in extractant solution in a 24-well plate: After the extraction period is complete, the liquid within each tissue insert will be decanted back into the well
from which it was taken, i.e., the solution will be mixed with the extractant in the well.
The tissue inserts will then be discarded.

-Transferring to 96-Well Plate:Two 200 μl aliquots from each well of the extraction plate(s) will be pipetted into a 96- well microtiter plate.

-Measuring Optical Density:The optical density of the extracted samples will be determined at a single wavelength of 570 nm and using eight 200 μl aliquots of the Extractant as blanks.

Calculating Percent Viability:
The percent viability of the test tissues will be determined using the following formula:
% Viability = 100 x (ODsample / ODNegative Control)

Quality Controls:
Negative Controls: The assay meets the acceptance criterion if the OD570 of the Negative Control is greater than 0.8 and less than 2.5.
Positive Controls: The assay meets the acceptance criterion if the mean relative viability of the positive control is below 50% of negative control viability.
Tissue Variability: The difference in viability between identically treated tissues must be less than 20%. This applies to tissues treated with the same test article as well as living and killed controls.

Ocular Irritation Potential:
An irritant is predicted if the mean relative tissue viability of two individual tissues exposed to the test substance is less than or equal to 60% of the mean viability of the
negative control-treated tissue viability.

In Vitro Result In Vivo Prediction (GHS3)
Mean tissue viability ≤ 60% Category 1 / Hazard Code 318, or
Category 2 / Hazard Codes 319 and 320
Mean tissue viability > 60% No Category (Non-Irritating)

Borderline Results:
If the test article-treated tissue viability is 60±5%, a second EIT should be performed. If the results of the second test disagree with the first, then a third test should be performed. The conclusion will be based on the agreement of two of the three tests.

Duration:The duration of the EpiOcularTM Eye Irritation Test is approximately five days.

Irritation parameter:

other: mean % tissue viability

Run / experiment:

Run 1

Value:

95.2

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:

Negative Controls: The assay meets the acceptance criterion if the OD570 of the Negative Control is greater than 0.8 and less than 2.5.
Positive Controls: The assay meets the acceptance criterion if the mean relative viability of the positive control is below 50% of negative control viability.
Tissue Variability: The difference in viability between identically treated tissues must be less than 20%.

Results of the MATTEK in vitro eye irritation study:

Test and Control Article Identity	Tissue Viability		Irritancy Classification	GHS Category
	Mean	SD
102-19-2	95.2	8.53	Non-irritant	Not Classified

 

Test and control article identity	Tissue no.	Raw data		Blank corrected data		Mean of aliquots	% viability	OD		Viabilities (%)
								MEAN	SD	Mean	SD
		Aliq 1	Aliq 2	Aliq 1	Aliq 2
102-19-2	1	1.566	1.555	1.520	1.509	1.514	91.0	1.585	0.142	95.2	8.53
	2	1.710	1.695	1.664	1.649	1.656	99.5

Interpretation of results:

other: not irritating

Conclusions:

The ocular irritation potential of test article was determined according to the OECD 492 test Guideline. The mean % tissue viability of test chemical was determined to be 95.2%. Thus, the test chemical was considered to be not irritating to MatTek EpiOcular Tisssue Model OCL-200.

Executive summary:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The MatTek EpiOcular™ model was used to assess the potential ocular 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 ocular irritation potential of test article. Tissues were exposed to test article and controls for ~6 hours, followed by a ~25 minute post-soak and approximately 18 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, as the OD of the negative control tissues was between 0.8 to 2.5 in run 1. Also, the positive control, methyl acetate, reduced tissue viability to be below 50% of negative control (for 6 hour exposures with solids) in run one and the standard deviation (SD) calculated from individual percent tissue viabilities of the test article exposed replicates was passing the acceptance criteria The mean % tissue viability of test chemical was determined to be 95.2%. Thus, the test chemical was considered to be not irritating to  MatTek EpiOcular Tisssue Model OCL-200 and being 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 reviewed to determine dermal irritation potential of the test chemical in living organisms. These include in vivo as in vitro experimental studies performed using the test chemical.

A skin irritation study was performed in humans to assess the irritation potential of test chemical 2% in petrolatum was tested on 29 human volunteers in a 48 hours closed patch test. The volunteers were observed for signs of irritation. Since no signs of skin irritation were observed, the test chemical was considered to be not irritating to human skin after 48 hours exposure.

The dermal irritation potential of test article was also determined according to the OECD 439 In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method”. 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 MTT data show the assay quality controls were met, as the OD of the negative control tissues was between 1.195 and 1.430. Also, the positive control, 5% sodium dodecyl sulfate (SDS), reduced tissue viability to 4.5% of negative control and the standard deviation (SD) calculated from individual percent tissue viabilities of the test article exposed replicates was passing the acceptance criteria. The Mean % tissue viability compared to negative control (n=3) of the test chemical was determined to be 81.8%. Hence, under the experimental test conditions it was concluded that test chemical was considered to be not irritating to the human skin and being classified as “Not Classified'' as per CLP Regulation.

The in vitro study is also supported by another skin irritation study performed on rabbits to assess the irritation potential of test chemical. Undiluted test chemical was applied under occlusion to the intact and abraded skin in rabbits for 24 hours. The rabbits were observed for signs of irritation. The test chemical induced moderate signs of irritation, hence the test chemical was considered to be moderately irritating to rabbit skin after 24 hours exposure.

The in vitro and human study results are further supported by an Acute Dermal Irritation/corrosion Study performed on Rabbits as per OECD Guideline No. 404 to determine the irritation potential of the test chemical. Three healthy young adult female rabbits were used for the study. Body weights were recorded on day 0 (prior to application) and at termination. Rabbits with good intact skin were selected for the study. The hairs of all the rabbits were clipped at contralateral sites, approximately 24 hours prior to treatment. A dose of 0.5ml test item (as such, undiluted) was applied to the skin, over an area of approximately 6 x 6 cm clipped of hair on one side of rabbits. The other untreated side was kept as control area and 0.5 ml of distilled water was applied at this site. At the end of 4 hours, the gauze patch was removed and test item application site was wiped with water without altering the integrity of the epidermis. Initially, the test item was applied to the clipped area of skin of one rabbit. The test site was covered with gauze patch. After 4 hours of exposure in animal no. 1, no erythema and oedema was observed at 1 hour of observation. At 24, 48 and 72 hours observation no erythema and no oedema was observed. Hence the confirmatory test was conducted on additional two rabbits (No. 2 and 3)to confirm the non-irritant nature of the test item. The patch was removed after 4 hours and rabbits were observed for erythema and oedema at 1, 24, 48 and 72 hours after patch removal, evaluated and graded as per Draize method. In Animal No. 2 & 3, at 1, 24, 48 and 72 hours, animal nos. 2 and 3 showed no erythema and no oedema. The other untreated side revealed no erythema and no oedema and was found to be normal throughout the experimental period. The individual mean score at 24, 48 and 72 hours for Animal Nos. 1, 2 and 3 were 0.00, 0.00, 0.00 and 0.00, 0.00, 0.00, for erythema and oedema formation, respectively. Hence, it was concluded that the test chemical was Non-Irritating to the skin of male New Zealand White rabbits under the experimental conditions tested and being classified as “Not Classified” as per CLP Classification.

The above results are supported by another OECD guideline 404 performed on Rabbits to evaluate the dermal irritation potential of the test chemical. Three healthy young adult female rabbits were used for conducting acute dermal irritation study. Body weights were recorded on day 0 (prior to application) and at termination. Rabbits with good intact skin were selected for the study. The hairs of all the rabbits were clipped at contralateral sites, approximately 24 hours prior to treatment. A dose of 0.5 ml of test item (as such) was applied to the skin, over an area of approximately 6 x 6 cm clipped of hair on one side of rabbits. The other untreated side was kept as control area and 0.5 ml of distilled water was applied at this site. At the end of 4 hours, the gauze patch was removed and test item application site was wiped with water without altering the integrity of the epidermis. Initially, the test item was applied to the clipped area of skin of one rabbit. The test site was covered with gauze patch. After 4 hours of exposure in Animal No. 1, there was no erythema and oedema observed at 1, 24, 48 and 72 hours observation. Hence the confirmatory test was conducted on additional two rabbits (No. 2 and 3) to confirm the non-irritant nature of the test item. In Animals No. 2 and 3 after post patch removal, revealed no erythema and oedema at 1, 24, 48 and 72 hours observation. The patch was removed after 4 hours and rabbits were observed for erythema and oedema at 1, 24, 48 and 72 hours after patch removal, evaluated and graded as per Draize method. The individual mean score at 24, 48 and 72 hours for Animal Nos. 1, 2 and 3 were 0.00, 0.00, 0.00 and 0.00, 0.00, 0.00, for erythema and oedema formation, respectively. Hence, it was concluded that the test chemical was Non-Irritating to the skin of Female New Zealand White rabbits under the experimental conditions tested and Classified as “Category- Not Classified” as per CLP Regulation.

Even though one of the studies in rabbits reports that test chemical could cause irritation to skin, but majority of the studies have report that test chemical was rather not irritating to skin. Hence, taking into consideration the majority of the results, the test chemical can be regarded 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 studies have been reviewed to determine ocular irritation potential of the test chemical in living organisms. These include in vivo as in vitro experimental studies performed using the test chemical.

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The MatTek EpiOcular™ model was used to assess the potential ocular 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 ocular irritation potential of test article. Tissues were exposed to test article and controls for ~6 hours, followed by a ~25 minute post-soak and approximately 18 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, as the OD of the negative control tissues was between 0.8 to 2.5 in run 1. Also, the positive control, methyl acetate, reduced tissue viability to be below 50% of negative control (for 6 hour exposures with solids) in run one and the standard deviation (SD) calculated from individual percent tissue viabilities of the test article exposed replicates was passing the acceptance criteria The mean % tissue viability of test chemical was determined to be 95.2%. Thus, the test chemical was considered to be not irritating to MatTek EpiOcular Tisssue Model OCL-200 and being classified as “Not classified’” as per CLP Regulation.

This in vitro result is supported by an Acute Eye Irritation/Corrosion Study performed on Rabbit as per OECD guideline No. 405 to evaluate the irritation potential of the test chemical. 3 male New Zealand White rabbits were used for the study. Rabbits free from injury of eye were selected for the study. The eyes of all the rabbits were examined 24 hours prior to treatment. One eye of each rabbit served as control and other as treated. Control eye was left untreated whereas 0.1 ml of the test item was instilled in the other (treated) eye of each rabbit. The eye was observed at 1, 24, 48 and 72 hour after test item instillation. Ophthalmoscope was used for scoring of eye lesions. In the initial test,0.1 ml of the test item was instilled into the conjunctival sac of the right eye of animal no.1 whereas the left eye of the rabbit served as the control. As animal no. 1 showed no severe ocular lesions hence a confirmatory test was conducted on additional two rabbits (animal no. 2 and 3);0.1 ml of the test item was instilled into the conjunctival sac of right eye of both the rabbits and left eye served as the control. Untreated eye of all the three rabbits was normal throughout the experimental period of 72 hours. The following grading scores were observed in treated eye of tested rabbits. Observation at 1 hour after instillation of test item revealed: Cornea- No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals;Iris: Normal in all the animals. Conjunctivae - Some blood vessels definitely hyperaemic (injected) was observed in all the animals; Chemosis: Some swelling above normal (includes nictitating membranes) was observed in all the animals. Observation at 24 hours after instillation of test item revealed:Cornea- No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals;Iris: Normal in all the animals. Conjunctivae - Some blood vessels definitely hyperaemic (injected) was observed in all the animals; Chemosis:No swelling (normal) was observed in all the animals. At 24 hours observation the rabbits were examined for corneal epithelium cell damage using sodium fluorescein strips and noticed 0% damage in all the animals. Observation at 48 and 72 hours after instillation of test item revealed:Cornea- No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals;Iris: Normal in all the animals. Conjunctivae - Blood vessels normal in all the animals; Chemosis:No swelling (normal) was observed in all the animals. The individual mean score for animal nos. 1, 2 and 3 at 24, 48, 72 hours (at treated site)for corneal opacity, iris, conjunctiva and chemosis were determined to be 0.00, 0.00, 0.33, 0.00; 0.00, 0.00, 0.33, 0.00 and 0.00, 0.00, 0.33, 0.00 respectively. Under the experimental conditions tested, eye irritation and reversibility of effects on eyes of rabbits was observed within 72 hours.Hence, it was concluded that the test chemical was Non-Irritating to the eyes of Male New Zealand White rabbits under the experimental conditions tested and was Classified as “Category- Not Classified" as per CLP criteria for Classification.

The above Guideline studies are further supported by a similar Acute Ocular Irritation/corrosion Study of test chemical in Rabbits, was performed as per OECD guideline No. 405. Rabbits free from injury of eye were selected for the study. The eyes of all the rabbits were examined 24 hours prior to treatment. One eye of each rabbit served as control and other as treated. Control eye was left untreated whereas; 0.1 ml of test item (as such) was instilled in the other (treated) eye of rabbits. The eye was observed at 1, 24, 48, 72 hours after test item instillation. Ophthalmoscope was used for scoring of eye lesions. In the initial test, 0.1 ml of test item was applied into the conjunctival sac of the right eye of Animal No.1. The left eye of the rabbit served as the control. Animal No. 1 presented ocular lesions at 1 hour observation period. Hence the confirmatory test was conducted on additional two rabbits (Animal No. 2 and 3); 0.1 ml of test item was instilled into the conjunctival sac of right eye and left eye served as the control. Ocular lesions were observed at 1, 24 and 48 hour in Animal Number 2 whereas in Animal Number 3 ocular lesions presented only at 1 hour observation period. Untreated eye of the treated rabbits was normal throughout the experimental period of 72 hours. The following grading scores were observed in treated eye of tested rabbits. Observation at 1 hour after instillation of test item revealed: Cornea-No ulceration or opacity in all 3 animals; Area of Opacity-Zero in all the animals;Iris:Normal in all the animals. Conjunctivae -Some blood vessels definitely hyperaemic (injected) in all the animals;Chemosis:Some swelling above normal (includes nictating membranes) were observed in animal number 1 and 3 whereas animal number 2 was normal. Observation at 24 hours after instillation of test item revealed: Cornea-No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals;Iris:Normal in all the animals. Conjunctivae -Some blood vessels definitely hyperaemic (injected) was observed in animal no. 2. Animal no. 1 and 3 recovered to normal;Chemosis:No swelling was observed in all the Animals. At 24 hours observation the rabbits were examined for corneal epithelium cell damage using sodium fluorescein strips and noticed 0 % damage in Animal Nos 1, 2 and 3, respectively. Observation at 48 and 72 hours after instillation of test item revealed: Cornea-No ulceration or opacity in all the animals; Area of Opacity-Zero in all the animals;Iris:Normal in all the animals. Conjunctivae -Some blood vessels definitely hyperaemic (injected) was observed in animal no. 3 at 48 hours which was recovered to normal at 72 hours observation whereas blood vessels were normal in Animal Numbers 1 and 3 at 48 and 72 hours observation;Chemosis:No swelling was observed in all the animals. The individual mean score for Animal Nos. 1, 2 and 3 at 24, 48, 72 hours for Corneal opacity, iris, conjunctiva, chemosis were found 0.00, 0.00, 0.00, 0.00 ; 0.00, 0.00, 0.67, 0.00 and 0.00, 0.00, 0.00, 0.00, respectively. Under the experimental conditions tested, eye irritation and reversibility of effects on eyes of rabbits was observed at 72 hours. Hence under the experimental test conditions, the test chemical was “Non Irritant” to New Zealand White Male rabbit eyes.

Based on the available studies the test chemical can be considered to be not irritating to eyes. It can be further classified under the category “Not Classified” as per CLP Regulation.

Justification for classification or non-classification

Available studies for the test chemical indicate a strong possibility of it being not irritating to eyes and skin. Hence, it can be classified under the category 'Not Classified" as per CLP Regulation.