(carboxylatomethyl)dimethyltetradecylammonium

Endpoint summary

Description of key information

Skin Corrosion

The purpose of this test is to evaluate the corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes.

Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

The relative mean viabilities for each treatment group were as follows:

Exposure Period	Percentage Viability
	Negative Control	Positive Control	Test Item
3 minute	100*	4.4	118.1
60 minute	100*	4.0	78.9

*The mean viability of the negative control tissues is set at 100%

The test item was considered to be non-corrosive to the skin.

Skin Irritation

This in vitro study was performed to assess the irritation potential of FSM-005W by means of the Human Skin Model Test.

The test item did not reduce MTT (test for direct MTT reduction), and it did not change colour when mixed with deionised water (test for colour interference). Also its intrinsic colour was not intensive. Consequently, additional tests with freeze-killed or viable tissues were not necessary.

Each three tissues of the human skin model EpiDerm™ were treated with the test item, the negative control (DPBS) or the positive control (5% SDS) for 60 minutes.

After treatment with the negative control the absorbance values were well within the required range of the acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for the 60 minutes treatment interval, thus assuring the quality of the tissues.

Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for the 60 minutes treatment interval, and thus assuring the validity of the test system.

After treatment with the test item FSM-005W the mean relative viability decreased to 3.5% compared to the negative control. This value is below the threshold for irritancy of ≤ 50%. Therefore, the test item is considered to possess an irritant potential.

In conclusion, it can be stated that in this study and under the experimental conditions reported, FSM-005W is irritant to skin.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 June 2017 - 30 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: FSM-005W
CAS Number: 2601-33-4
Batch:170321
Purity:19.9% aqueous solution of FSM-005W (solid)
Physical state/Appearance: Clear colorless liquid
Expiry Date: 20 November 2018
Storage Conditions: Approximately 4 °C in the dark

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

EpiDerm™ Reconstructed Human Epidermis Model Kit
Supplier: MatTek
Date received: 27 June 2017
EpiDermTM Tissues (0.63cm2) lot number: 25825
Assay Medium lot number: 062217ALA
Upon receipt of the EpidermTM tissues, the sealed 24 well plate was stored in a refrigerator until use.

Pre-Test Procedure
Assessment of Direct Test Item Reduction of MTT
MTT Dye Metabolism, Cell Viability Assay
The MTT assay, a colorimetric method of determining cell viability, is based on reduction of the yellow tetrazolium salt (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to a blue formazan dye by mitochondrial succinate dehydrogenase in viable cells One limitation of the assay is possible interference of the test item with MTT. A test item may directly reduce MTT, thus mimicking dehydrogenase activity of the cellular mitochondria. This property of the test item is only a problem if at the time of the MTT test (after rinsing) there is still a sufficient amount of the test item present on or in the tissues. In this case, the true metabolic MTT reduction and the false direct MTT reduction can be differentiated and quantified.
Test for Direct MTT Reduction
As specified, a test item may interfere with the MTT endpoint, if it was able to directly reduce MTT and at the same time was present on or in the tissues when the MTT viability test was performed. To identify this possible interference, the test item was checked for the ability to directly reduce MTT according to the procedure below:
50 µL of the test item was added to 1 mL of a freshly prepared 1.0 mg/mL MTT solution. The solution was incubated in the dark at 37 °C, 5% CO2 in air for 60 minutes. Untreated MTT solution was tested concurrently to act as a control.
If the MTT solution containing the test item turns blue/purple relative to the control, the test item was presumed to have reduced the MTT.
Assessment of Color Interference with the MTT Endpoint
A test item may interfere with the MTT endpoint if it is colored. The MTT assay is affected only if the test item is present in the tissues when the MTT viability assay is performed.
50 µL of test item was added to 300 µL of sterile water. The solution was incubated in the dark at 37 oC, 5% CO2 in air for 60 minutes. A visual assessment of the color was then made.

Main Test
Pre-Incubation
The assay medium was pre-warmed before use. 0.9 mL of this assay medium was pipetted into the appropriate wells of two pre-labeled 6-well plates for both the 3 Minute and 60 Minute exposure periods. EpiDerm™ tissues were transferred into the 6 well plates containing the assay medium. The 6 well plates containing the EpiDerm™ samples were pre-incubated (37 °C, 5% CO2) for approximately 1 hour before dosing.
Application of Test Item and Rinsing
Before pre-incubation was complete, a 24 well plate was prepared for use as a “holding plate” for both the 3 Minute and 60 Minute exposure periods. This plate was used to maintain the viability of the tissue inserts between rinsing following chemical exposure and MTT loading. Another 24 well plate was prepared for the MTT loading. 300 µL of either pre warmed assay medium (holding plate) or MTT medium (MTT loading plate) was dispensed into each well. The two plates were placed into the incubator until required.
After pre incubation of the EpiDerm™ tissues, the medium was aspirated and replaced with 0.9 mL of fresh assay medium. The 6-well plate for the 3 Minute exposure period was returned to the incubator, while the other was being dosed for the 60 Minute exposure. For the 60 Minute exposure period, 50 µL of sterile distilled water (negative control) was added to the first two tissues. The tissues were dosed at regular intervals to allow for the time taken to rinse each tissue following exposure and to ensure that each tissue gets an equal exposure time. 50 µL of the test item and 50 µL of 8.0 N Potassium Hydroxide (positive control) were also applied to the corresponding tissues in turn. The plate was returned to the incubator (37 °C, 5% CO2) for the 60 Minute exposure period.
When dosing for the 60 Minute exposure period was complete, the same procedure was repeated for the 3 Minute exposure period. Because the exposure time was so short, the tissues were dosed at regular intervals to ensure that each tissue received an equal exposure time and to allow for the time taken to rinse each tissue following exposure. Rinsing was achieved by filling and emptying each tissue under a constant soft stream of DPBS to gently remove any residual test item. Excess DPBS was removed by blotting the bottom of the tissue insert with tissue paper. Each tissue was placed into the prepared holding plate until all tissues were rinsed. They were then blotted and transferred to the 24 well plate prepared for MTT loading. The plate was incubated (37 °C, 5% CO2) for 3 hours. Once the 60 Minute exposure period was complete, the same rinsing and MTT loading procedure was repeated.
After the 3 Hour MTT incubation was complete, the inserts were blotted and transferred to labeled 24 well plates for MTT extraction. 2 mL of MTT extractant (isopropanol) was used to completely immerse each insert and the plate was covered with plate sealer to prevent Isopropanol evaporation. The plates stood overnight at room temperature, to allow extraction to proceed.

Absorbance/Optical Density Measurements
After extraction, each tissue was pierced with a pipette fitted with a 1000 µL tip and the extraction solution was forced vigorously up and down to form a homogenous solution. 3 x 200 µL aliquots of the extract were transferred to the appropriate wells of a pre labeled 96 well plate. 200 µL of isopropanol alone was added to the three wells designated as blanks. Absorbency at 570nm (OD570) of each well was measured using the Labtech LT 4500 microplate reader.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Negative Control
50 µL of sterile distilled water. The negative control item was used as supplied.

Postive Control
50 µL of 8.0 N Potassium Hydroxide. The positive control item was used as supplied.

Test Item
50 µL of the test item. The test item was used as supplied.

Duration of treatment / exposure:

3 mins and 60 minutes

Number of replicates:

2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

118.1

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minutes

Value:

78.9

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

Direct MTT Reduction
The MTT solution containing the test item did not turn blue/purple. This was taken to indicate the test item did not reduce MTT.

Assessment of Color Interference with the MTT endpoint
The solution containing the test item did not become colored. This was taken to indicate the test item did not have the potential to cause color interference.

Quality Criteria
The mean OD570 for the negative control treated tissues was 1.422 for the 3 Minute exposure period and 1.734 for the 60 Minute exposure period. The negative control acceptance criteria were therefore satisfied.
The relative mean tissue viability for the positive control treated tissues was 4.0% relative to the negative control following the 60 Minute exposure period. The positive control acceptance criterion was therefore satisfied.
In the range 20 to 100% viability the Coefficient of Variation between the two tissue replicates of each treatment group did not exceed 30%. The acceptance criterion was therefore satisfied.

Test Item, Positive Control Item and Negative Control Item

The relative mean viabilities for each treatment group were as follows

Exposure Period	Percentage Viability
	Negative Control	Positive Control	Test Item
3 minute	100*	4.4	118.1
60 minute	100*	4.0	78.9

*The mean viability of the negative control tissues is set at 100%

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was considered to be non-corrosive to the skin.

Executive summary:

Introduction

The purpose of this test is to evaluate the corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes.

Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

Methods

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. Negative and positive control groups were treated for each exposure period. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT‑loading. After MTT loading each tissue was placed in 2 mL Isopropanol for MTT extraction.

At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 mL samples were transferred to the appropriate wells of a pre-labeled 96‑well plate. The optical density (OD) was measured at 570 nm (OD₅₇₀).

Data are presented in the form of percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues).

Results

The relative mean viabilities for each treatment group were as follows:

Exposure Period	Percentage Viability
	Negative Control	Positive Control	Test Item
3 minute	100*	4.4	118.1
60 minute	100*	4.0	78.9

*The mean viability of the negative control tissues is set at 100%

Quality criteria: The quality criteria required for acceptance of results in the test were satisfied.

Conclusion

The test item was considered to be non-corrosive to the skin.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: 18 December 2017. Experimental completion date: 16 February 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: FSM-005W
CAS No.: 2601-33-4
UN No.: UN1760 (Class 8, Corrosive)
Batch: 170321
Purity: 19.9%
Appearance: Colourless, liquid
Expiry Date: 20 November 2018
Storage Conditions: In the refrigerator
Stability in Solvent: Stable in water, not quantified

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

Epi-200- SIT Kit Components Needed for the Assay
Epi-200- SIT Kit. Lot No.: 25878
1 Sealed 24-well plate: Contains 24 inserts with EpiDerm™ tissues on agarose
2 24-well plates: For MTT viability assay
8 6-well plates: For storing inserts, or for topically applying test agents
1 bottle Serum-Free Assay Medium: DMEM-based medium
1 bottle DPBS Rinse Solution: For rinsing the inserts in MTT assay
1 vial 5% SDS Solution (TC-SDS-5%): Skin irritant reference chemical – Positive Control

MTT-100 Assay Kit Components
1 vial, 2 mL MTT concentrate
1 vial, 8 mL MTT diluent (supplemented DMEM): For diluting MTT concentrate prior to use in the MTT assay
1 bottle Extractant Solution (Isopropanol): For extraction of formazan crystals

Cell Culture
Epi-200 SIT kits and MTT-100 assay diluent were purchased from MatTek Corporation (82105 Bratislava, Slovakia). The EpiDerm™ tissue consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm™ tissues (surface 0.6 cm²) are cultured on specially prepared cell culture inserts (MILLICELLs, 10 mm diameter).
EpiDerm™ tissues were shipped with cool packs on medium-supplemented agarose gels in a 24-well plate and reached Envigo CRS GmbH on February 13, 2018. On day of receipt the pre-incubation phase of the EpiDerm™ tissues started.
The incubators used in this study are checked and qualified by an external service. Only released incubators are used during this study. Culture conditions are 37 ± 1.5 °C, 5 ± 0.5% CO2. Technicians take care for being enough water inside the incubator to guarantee the humidity. Additionally viability of the negative control showed that required culture conditions were given during the study. The target humidity should be 95 ± 5% RH.

Vehicle:

unchanged (no vehicle)

Details on test system:

MTT-Solution
The MTT-solution was prepared freshly on day of use (resulting: 1 mg/mL).

Test for Direct MTT Reduction and Colour Interference
A test item may interfere with the MTT endpoint if: a) it is coloured and/or b) able to directly reduce MTT. The MTT assay is affected only if the test item is present in the tissues when the MTT viability test is performed.
Some non-coloured test items may change into coloured test items in wet or aqueous conditions and thus stain tissues during the 60 min exposure. Therefore, before exposure, a functional check for this possibility has to be performed.
30 µL of the test item were added to 0.3 mL of deionised water (transparent glass test-tube). The mixture was incubated in the incubator (37 ± 1.5 °C, 5 ± 0.5 % CO2) for 60 min. At the end of the exposure time, the mixture was shaken and the presence and intensity of the staining (if any) was evaluated.
Since the test item did not dye water or did not change colour in the presence of water, an additional test with viable tissues (but without MTT addition) was not necessary to be performed.
All test items were further evaluated for their potential to interfere with MTT assay. To test if a test item directly reduces MTT, 30 µL of the test item were added to 1 mL of the MTT-solution (1mg/mL) and was incubated in the incubator (37 ± 1.5 °C, 5 ± 0.5% CO2) for 60 minutes. Untreated MTT medium was used as control.
Since the MTT solution did not turn blue/purple, the test item was not considered to reduce MTT and an additional test with freeze-killed tissues did not have to be performed.

Experimental Performance
Pre-warming of EpiDerm™ Tissues
The plastic bag containing the 24-well plate with epidermal tissues was opened under sterile conditions. Under an airflow using forceps, the gauze was removed and the inserts were taken out. Any remaining agarose that adheres to the outer sides of the inserts was removed by gentle blotting on the sterile filter paper or gauze, and the tissues were placed in the empty, sterile 6-well plate. Prior to the exposure of the test item and of the controls the EpiDerm™ tissues were inspected for quality: If necessary, it was taken care, that
1. air bubbles between agarose and insert were not > 30% of the total surface,
2. liquid on top of the insert was removed with sterile cotton tips,
3. if again moisture is observed on top of the inserts after the pre-incubation or in
case of visible defects the respective skin models were discarded.
0.9 mL of the assay medium (20 – 25 °C) was pipetted into each well of sterile 6-well plates. The inserts with the EpiDerm™ tissues were placed in the upper wells, and were pre-incubated for 60 minutes in the incubator (37 ± 1.5 °C, 5 ± 0.5% CO2, 95 ± 5% RH). Following, the inserts were transferred from upper wells into the lower wells of the 6-well plates, and, the pre-incubation was continued for further 23 hours (37 ± 1.5 °C, 5 ± 0.5% CO2, 95 ± 5% RH).

Treatment
After pre-incubation of EpiDerm™ tissues was completed, medium was replaced by 0.9 mL of fresh medium per well. The negative control, positive control and the test item were added into the insert atop the corresponding EpiDerm™ triplicate tissues. The treatment time was 60 minutes in total. Within this period the 6-well plates were put into the incubator for 35 minutes at 37 ± 1.5 °C, 5 ± 0.5 % CO2. In the remaining period the plates were placed in a sterile bench at room temperature until the end of treatment.
After the end of the treatment interval the inserts were removed immediately from the 6-well plate and tissues were gently rinsed with DPBS at least 15 times in order to remove any residual test material. After the rinsing the inserts were submerged in DPBS at least three times. Afterwards the inserts were once again rinsed with sterile DPBS from the inside and the outside. Excess DPBS was removed by gently shaking the inserts and blotting the bottom with sterile blotting paper. The tissues were then transferred into new 6-well plates with 0.9 mL of fresh assay medium in the upper row. The inserts were placed in the prepared holding plate. Tissues were incubated for 24 hours at 37 ± 1.5 °C, 5 ± 0.5 % CO2. After incubation medium was changed (0.9 mL of pre-warmed fresh medium). Thereafter tissues were incubated for another 17.5 hours at 37 ± 1.5 °C, 5 ± 0.5 % CO2. The complete incubation time was 41.5 hours.

MTT Assay
On the day of testing the MTT concentrate was diluted with the MTT diluent (1 mg/mL). The 24-well plates were prepared before the end of the tissue pre-warming period. A volume of 300 µL of the MTT solution was added to each well and the plates were kept in an incubator (37 ± 1.5 °C, 5 ± 0.5 % CO2) until further use.
After the 41.5-hours incubation period was completed for all tissues and exposure groups, culture inserts were transferred from the holding plates to the MTT-plates. After a 3-hour incubation period (37 ± 1.5 °C, 5 ± 0.5 % CO2), the tissues were rinsed three times with DPBS, and carefully dried with blotting paper. The tissues were transferred into new 24-well plates containing 2 mL of extractant solution (isopropanol) in each well ensuring that the tissues are completely covered. The 24-well plate was sealed to inhibit the isopropanol evaporation.
The formazan salt was extracted for about 2.5 hours while shaking at room temperature.
After the extraction period was completed, the inserts were pierced with an injection needle to allow the extract to run into the well from which the insert was taken. Afterwards the insert was discarded. The 24-well plates were placed on a shaker for 15 minutes until the solution was homogeneous in colour.
Per each tissue, 3 x 200 µL aliquots of the blue formazan solution were transferred into a 96-well flat bottom microtiter plate from the 15 minutes exposure. OD was read in a microplate reader (Versamax® Molecular Devices, Softmax Pro Enterprise, version 4.7.1) with a 570 nm filter. Mean values were calculated from the 3 wells per tissue.

Data Recording
The data generated were recorded in the laboratory protocol. The results are presented in tabular form, including experimental groups with the test item, negative control and positive controls.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

30 µL (47 µL/cm2 according to guideline) of the undiluted test item was dispensed directly atop the EpiDerm™ tissue and spread to match the surface of the tissue for a complete treatment time of 60 minutes.
30 µL of negative and positive controls were applied to triplicate tissue.

Duration of treatment / exposure:

60 minutes

Duration of post-treatment incubation (if applicable):

41.5

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

mean

Value:

3.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

The optical pre-experiment (colour interference pre-experiment) to investigate the test item’s colour change potential in water did not lead to a change in colour.

Optical evaluation of the MTT-reducing capacity of the test item after 1 hour incubation with MTT-reagent did not show blue/purple colour.

The mean relative viability of the test item decreased to 3.5% (threshold for irritancy: ≤ 50%), consequently the test item was irritant to skin.

Discussion
This in vitro study was performed to assess the irritation potential of FSM-005W by means of the Human Skin Model Test.
The test item passed the MTT- and the Colour Interference pre-tests.
The test item, the negative control (DPBS), and the positive control (5% SDS) were applied to triplicate tissue each.
The test item and the positive and negative controls were washed off the skin tissues after 60 minutes treatment. After further incubation for about 41.5 hours the tissues were treated with the MTT solution for 3 hours following 2.5 hours extraction of the colorant from the cells. The amount of extracted colorant was determined photometrically at 570 nm.
After treatment with the negative control the absorbance values were well within the required acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for the 60 minutes treatment interval thus showing the quality of the tissues.
Treatment with the positive control induced a decrease in the relative absorbance compared with the negative control to 3.1% thus ensuring the validity of the test system.
The standard deviations between the % viability values of the test item, the positive and negative controls in the main test were below 10.3 (threshold of the "OECD Guideline for the Testing of Chemicals 439: In vitro Skin Irritation: Reconstructed Human Epidermis Test Method”: ≤ 18), thus ensuring the validity of the study.
Compared to the relative viability of the negative control the mean relative viability was reduced to 3.5% after exposure of the skin tissues to the test item. This value is below the threshold for irritancy of ≤ 50%. Therefore, the test item is considered to possess an irritant potential.

Treatment Group	Tissue No.	OD 570 nm Well 1	OD 570 nm Well 2	OD 570 nm Well 3	Mean OD of 3 Wells	Mean OD of 3 Wells blank corrected	Mean OD of 3 tissues blank corrected	Rel. Viability [%] Tissue 1, 2 + 3*	Standard Deviation [%]	Mean Rel. Viability [%]**
Blank		0.038	0.038	0.037	0.038
Negative Control	1	1.806	1.757	1.775	1.779	1.742	1.569	111.0	10.3	100.0
	2	1.609	1.562	1.576	1.582	1.545		98.5
	3	1.488	1.435	1.452	1.458	1.421		90.5
Positive Control	1	0.085	0.084	0.084	0.084	0.046	0.048	3.0	0.1	3.1
	2	0.086	0.085	0.090	0.087	0.049		3.1
	3	0.087	0.086	0.086	0.087	0.049		3.1
Test Item	1	0.096	0.098	0.092	0.095	0.058	0.055	3.7	0.3	3.5
	2	0.098	0.097	0.096	0.097	0.059		3.8
	3	0.090	0.086	0.086	0.087	0.049		3.1

* Relative viability [rounded values]: [100 x (absorbance test item/positive control/negative control)]/(mean absorbance negative control)

** Mean relative viability [rounded values]: [100 x (mean absorbance test item/positive control/negative control)]/(mea absorbance negative control)

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

In conclusion, it can be stated that in this study and under the experimental conditions reported, FSM-005W is irritant to skin according to UN GHS and EU CLP regulation.

Executive summary:

This in vitro study was performed to assess the irritation potential of FSM-005W by means of the Human Skin Model Test.

The test item did not reduce MTT (test for direct MTT reduction), and it did not change colour when mixed with deionised water (test for colour interference). Also its intrinsic colour was not intensive. Consequently, additional tests with freeze-killed or viable tissues were not necessary.

Each three tissues of the human skin model EpiDerm™ were treated with the test item, the negative control (DPBS) or the positive control (5% SDS) for 60 minutes.

After treatment with the negative control the absorbance values were well within the required range of the acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for the 60 minutes treatment interval, thus assuring the quality of the tissues.

Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for the 60 minutes treatment interval, and thus assuring the validity of the test system.

After treatment with the test item FSM-005W the mean relative viability decreased to 3.5% compared to the negative control. This value is below the threshold for irritancy of ≤ 50%. Therefore, the test item is considered to possess an irritant potential.

In conclusion, it can be stated that in this study and under the experimental conditions reported, FSM-005W is irritant to skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (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

Study period:

Experimental start date:11 August 2017. Experimental completion date: 11 August 2017.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: FSM-005W
CAS Number: 2601-33-4
Batch: 170321
Purity: 19.9% aqueous solution of FSM-005W (solid)
Physical state/Appearance: clear colorless liquid
Expiry Date: 20 November 2018
Storage Conditions: approximately 4 oC in the dark

Species:

cattle

Details on test animals or tissues and environmental conditions:

Eyes from adult cattle (typically 12 to 60 months old) were obtained from a local abattoir as a by-product from freshly slaughtered animals. The eyes were excised by an abattoir employee after slaughter, and were placed in Hanks’ Balanced Salt Solution (HBSS) supplemented with antibiotics (penicillin at 100 IU/mL and streptomycin at 100 µg/mL). They were transported to the test facility over ice packs on the same day of slaughter. The corneas were refrigerated on arrival and used within 24 hours of receipt.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

0.75 mL of test item preparation. For the purpose of this study the test item was prepared as a 50% v/v solution in sodium chloride 0.9% w/v. This gave a solution with a final surfactant content of 10%.
0.75 mL of negative control item. The negative control item, sodium chloride 0.9% w/v, was used as supplied.
0.75 mL of positive control item. The positive control item, ethanol, was used as supplied.

Duration of treatment / exposure:

10 minutes

Duration of post- treatment incubation (in vitro):

120 minutes

Number of animals or in vitro replicates:

3

Details on study design:

Preparation of Corneas
All eyes were macroscopically examined before and after dissection. Only corneas free of damage were used.
The cornea from each selected eye was removed leaving a 2 to 3 mm rim of sclera to facilitate handling. The iris and lens were peeled away from the cornea. The isolated corneas were immersed in a dish containing HBSS until they were mounted in Bovine Corneal Opacity and Permeability (BCOP) holders.
The anterior and posterior chambers of each BCOP holder were filled with complete Eagle’s Minimum Essential Medium (EMEM) without phenol red and plugged. The holders were incubated at 32 ± 1 ºC for 60 minutes. At the end of the incubation period each cornea was examined for defects. Only corneas free of damage were used.

Selection of Corneas and Opacity Reading
The medium from both chambers of each holder was replaced with fresh complete EMEM.
A pre treatment opacity reading was taken for each cornea using a calibrated opacitometer. The average opacity for all corneas was calculated.
Three corneas were randomly allocated to the negative control. Three corneas were also allocated to the test item and three corneas to the positive control item.

Treatment of Corneas
The EMEM was removed from the anterior chamber of the BCOP holder and 0.75 mL of the test item preparation or control items were applied to the appropriate corneas. The holders were gently tilted back and forth to ensure a uniform application of the item over the entire cornea. Each holder was incubated, anterior chamber uppermost, at 32 ± 1 ºC for 10 minutes.
At the end of the exposure period the test item and control items were removed from the anterior chamber and the cornea was rinsed three times with fresh complete EMEM containing phenol red before a final rinse with complete EMEM without phenol red. The anterior chamber was refilled with fresh complete EMEM without phenol red. A post treatment opacity reading was taken and each cornea was visually observed.
The holders were incubated, anterior chamber facing forward, at 32 ± 1 ºC for 120 minutes.
After incubation the holders were removed from the incubator, the medium from both chambers was replaced with fresh complete EMEM and a final opacity reading was taken. Each cornea was visually observed.

Application of Sodium Fluorescein
Following the final opacity measurement the permeability of the corneas to sodium fluorescein was evaluated. The medium from the anterior chamber was removed and replaced with 1 mL of sodium fluorescein solution (4 mg/mL). The dosing holes were plugged and the holders incubated, anterior chamber uppermost, at 32 ± 1 ºC for 90 minutes.

Permeability Determinations
After incubation the medium in the posterior chamber of each holder was decanted and retained.
360 µL of media representing each cornea was dispensed into the appropriate wells of a pre labeled 96 well plate. The optical density was measured (quantitative viability analysis) at 492 nm (without a reference filter) using the Labtech LT-4500 microplate reader and LT-com Analysis Software.

Histopathology
The corneas were retained after testing for possible conduct of histopathology. Each cornea was placed into a pre labeled tissue cassette fitted with a histology sponge to protect the endothelial surface. The cassette was immersed in 10% neutral buffered formalin.

Irritation parameter:

in vitro irritation score

Run / experiment:

mean

Value:

24.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Corneal Epithelium Condition
The corneas treated with the test item were cloudy post treatment and post incubation. The corneas treated with the negative control item were clear post treatment and post incubation. The corneas treated with the positive control item were cloudy post treatment and post incubation.

Criteria for an Acceptable Test
The positive control In Vitro Irritancy Score was within the range of 31.6 to 58.7. The positive control acceptance criterion was therefore satisfied.
The negative control gave opacity of ≤3.0 and permeability ≤0.077. The negative control acceptance criteria were therefore satisfied.

In Vitro Irritancy Score

Treatment	Cornea Number	Opacity					Permeability (OD)		In Vitro Irritancy Score
		Pre-Treatment	Post-Treatment	Post Incubation	Post-Incubation - Pre‑Treatment	Corrected Value		Corrected Value
Negative Control	1	4	5	6	2		0.008
	2	4	3	6	2		0.010
	3	7	4	5	0		0.010
					1.3*		0.00~		1.5
Positive Control	4	7	34	34	27	25.7	0.631	0.622
	5	4	37	40	36	34.7	0.972	0.963
	6	4	43	39	35	33.7	0.906	0.897
						31.3#		0.827#	43.7
Test Item	7	3	17	12	9	7.7	1.001	0.992
	8	2	12	11	9	7.7	1.275	1.266
	9	2	12	10	8	6.7	1.194	1.185
						7.3#		1.147#	24.5

OD= Optical density           

* = Mean of the post-incubation -pre‑treatment values           

~= Mean permeability                     

#= Mean corrected value

Interpretation of results:

study cannot be used for classification

Conclusions:

No prediction of eye irritation can be made.

Executive summary:

Introduction

The purpose of this test was to identify test items that can induce serious eye damage and to identify test items not requiring classification for eye irritation or serious eye damage. The Bovine Corneal Opacity and Permeability (BCOP) test method is an organotypic model that provides short‑term maintenance of normal physiological and biochemical function of the bovine cornea in vitro. In this test method, damage by the test item is assessed by quantitative measurements of changes in corneal opacity and permeability.

The test method can correctly identify test items (both chemicals and mixtures) inducing serious eye damage as well as those not requiring classification for eye irritation or serious eye damage, as defined by the United Nations (UN) Globally Harmonized System of Classification and Labelling of Items (GHS) and EU Classification, Labelling and Packaging (CLP) of chemicals (Regulation (EC) No 1272/2008), and it was therefore endorsed as scientifically valid for both purposes. Test items inducing serious eye damage are classified as UN GHS and EU CLP Category 1. Items not classified for eye irritation or serious eye damage are defined as those that do not meet the requirements for classification as UN GHS/EU CLP Category 1 or 2 (2A or 2B), i.e. they are referred to as UN GHS/EU CLP No Category.

Method

The test item was applied at a final surfactant concentration of 10% v/v in sodium chloride 0.9% w/v for 10 minutes followed by an incubation period of 120 minutes. Negative and positive control items were tested concurrently. The two endpoints, decreased light transmission through the cornea (opacity) and increased passage of sodium fluorescein dye through the cornea (permeability) were combined in an empirically derived formula to generate anIn Vitro Irritancy Score (IVIS). 

Data Interpretation

The test item is classified according to the prediction model as follows:

IVIS	UN GHS	EU CLP (Regulation (EC) No 1272/2008)
≤ 3	No Category	Not classified for irritation
>3; ≤ 55	No prediction can be made	No prediction can be made
> 55	Category 1	Category 1 H318: Causes serious eye damage

Results

The In Vitro irritancy scores are summarized as follows:

Treatment	In Vitro Irritancy Score
Test Item	24.5
Negative Control	1.5
Positive Control	43.7

Conclusion

No prediction of eye irritation can be made.