Reaction product of 6H-dibenz[c,e][1,2]oxaphosphorin 6-oxide, itaconic acid and ethylene glycol

Endpoint summary

Description of key information

Skin irritation: Under the present test conditions, Ukanol FR 70 tested at an exposure time of 60 minutes and a 42-hour post-treatment incubation period, was non-cytotoxic and, hence, predicted to be non-irritant to skin in an experiment employing an artificial three-dimensional model of human skin. Hence, the test item did not show irritant properties and is therefore not classified as irritant (UN GHS no category).

Eye irritation: Under the present test conditions Ukanol FR 70 tested in the in vitro BCOP test method, had an IVIS value of 0.807, which is below the cut-off value of 3 (UN GHS no category) and consequently it is not classified as a severe irritant and is not corrosive according to UN GHS classification.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-12-23 - 2017-02-08

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)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on test system:

As the test item is highly viscous, Ukanol FR 70 was applied to a nylon mesh prior to application to the skin surface. 25 mg of test item were applied to the nylon mesh and incubated at 37°C, 5% CO2 and 95% relative humidity for 60 minutes to test for possible interaction between test substance and the mesh.

Control samples:

yes, concurrent no treatment

yes, concurrent positive control

Amount/concentration applied:

positive control: 30µl
negative control: 30µl
test item: 25 mg on a nylon mesh

Duration of treatment / exposure:

60 minutes

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

negative control

Value:

100

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

positive control

Value:

7.2

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item

Value:

98.3

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

GHS criteria not met

Conclusions:

Under the present test conditions, Ukanol FR 70 tested at an exposure time of 60 minutes and a 42-hour post-treatment incubation period, was non-cytotoxic and, hence, predicted to be non-irritant to skin in an experiment employing an artificial three-dimensional model of human skin. Hence, the test item did not show irritant properties and is therefore not classified as irritant (UN GHS no category).

Executive summary:

The purpose of this study was to determine cytotoxic properties of Ukanol FR 70 to skin cells, which might lead to irritation of human skin, by using an artificial three-dimensional model of human skin. The EpiDermTM model was employed.

Three tissues were used for each treatment and concurrent control groups. The optical density (OD) was determined by using the MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, Thiazolyl blue) reduction assay and expressed as relative percentage of viability of the negative control-treated tissues.

As the test item is highly viscous, Ukanol FR 70 was applied to a nylon mesh prior to application to the skin surface. The nylon mesh loaded with 25 mg of test item was applied to the skin model which was moistened with Dulbecco’s phosphate buffered saline (D-PBS).D-PBS was used as the negative control.5% aqueous sodium dodecyl sulphate (SDS)was used as the positive reference item. An exposure time of 60 minutes was employed followed by a 42-hour post-treatment incubation period in fresh medium. The mean viability of cells exposed to Ukanol FR 70 was 98.3% of the negative controls and, hence, was well above the cut-off percentage cell viability value that distinguishes irritant from non-irritant test items of > 50%. Ukanol FR 70 was considered to be non-cytotoxic and predicted to be non-irritant to skin.

The mean optical density (OD) of 3 negative control tissues was 1.472 and was well within the acceptable range of ≥ 1.0 to ≤ 2.5.The viability of cells treated with the positive reference item, 5% SDS, was 7.2 of the negative control and fulfilled the acceptance criterion of ≤20%.

The standard deviation of all triplicates determined was below the limit of acceptance of 18%.Hence, all acceptance criteria were fulfilled.

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

Study period:

2016-12-23 - 2017-02-09

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

GLP compliance:

yes (incl. QA statement)

Species:

cattle

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

yes, concurrent positive control

Amount / concentration applied:

negative control: 750 µL
positive control: 750 µL
test item: 150 mg

Duration of treatment / exposure:

240 minutes

Number of animals or in vitro replicates:

3

Details on study design:

SELECTION AND PREPARATION OF CORNEAS:
Bovine eyes from cattle in the age range of 6 to 12 months were obtained from a slaughterhouse . To minimize deterioration and bacterial contamination, on collection the eyes were completely submerged in Hanks’ Balanced Salt Solution (HBSS) containing penicillin at 100 IU/mL and streptomycin at 100 µg/mL. The corneas were dissected with a 2 to 3 mm rim of sclera and mounted in corneal holders with anterior (epithelium) and posterior (endothelium) chambers. Beginning with the posterior chambers, the chambers were filled to excess with pre-warmed Eagle’s Minimum Essential Medium (EMEM) , while preventing bubble formation. The corneal holder was equilibrated at 32±1°C for at least one hour.After the equilibration period, fresh pre-warmed EMEM was added to both chambers and baseline opacity readings were taken for each cornea. Corneas exhibiting macroscopic tissue damage (e.g. scratches, pigmentation, neovascularisation) or an opacity >7 opacity units were discarded. The mean opacity of all equilibrated corneas was calculated by use of an opacitometer.

QUALITY CHECK OF THE ISOLATED CORNEAS:
Upon arrival at the laboratory, the eyes were examined for defects such as but not limited to increased opacity, scratches, and neovascularisation. Only corneas from eyes free of defects were used.The quality of each cornea was also evaluated at later steps in the assay. Corneas that had opacity greater than seven opacity units or equivalent for the opacitometer and cornea holders used after an initial one hour equilibration period had to be discarded.

NUMBER OF REPLICATES:
3

NEGATIVE CONTROL USED:
0.9% sodium chloride solution

POSITIVE CONTROL USED:
20% Imidazole (CAS no. 288-32-4) in 0.9% sodium chloride solution

APPLICATION DOSE AND EXPOSURE TIME:
In a preliminary study, no homogeneous suspension of the test item could be achieved in a 0.9% sodium chloride solution due to the high viscosity of the test item. Hence, 150 mg Ukanol FR 70 (corresponding to 750 µL of the recommended concentration of 20% (w/v) by the test guideline 437 for non-surfactant solids) were applied to a plastic sheet prior to application to the cornea.The cornea was moistened with 600 µL 0.9% NaCl solution prior to application.

TREATMENT METHOD: [closed chamber / open chamber]:
The open-chamber method was used. The window-locking ring and glass window from the anterior chamber were removed prior to treatment. The control or test chemical was applied directly to the epithelial surface of the cornea using a micro-pipet or the plastic sheet with the test item-treated side, respectively. After dosing, the glass window was replaced on the anterior chamber to recreate a closed system.

POST-INCUBATION PERIOD: no.

REMOVAL OF TEST SUBSTANCE:
After the exposure period of 240 minutes (the recommended exposure time for non-surfactant solids) the test item, the solvent control, the negative and positive controls, were removed from each chamber. Subsequently, the epithelium was washed with EMEM containing phenol red at least three times. Washing was repeated until no test item or discolouration (yellow or purple) of phenol red was visible. The corneas were rinsed a final time with EMEM only to remove any remaining phenol red from the chamber. The chamber was then filled with EMEM without phenol red.
- Number of washing steps after exposure period:at least three times
- POST-EXPOSURE INCUBATION:
To determine the corneal permeability 1 mL sodium fluorescein solution (5 mg/mL in 0.9% sodium chloride solution) was added to the anterior chamber (epithelial surface) while the posterior chamber (endothelial surface) was refilled with fresh EMEM. The holder was incubated in a horizontal position at 32±1°C for 90±5 minutes. The amount of sodium fluorescein that crossed from the anterior to the posterior chamber was measured quantitatively using a microplate reader (Tecan Sunrise Magellan Version 6.4 ). Measurements at 490 nm were recorded as optical density (OD490). The fluorescein permeability values were determined using OD490 values based upon a visible light spectrophotometer (Tecan Sunrise) using a standard 1 cm path length.

SCORING SYSTEM: In Vitro Irritancy Score (IVIS):
After correcting the opacity and mean permeability (OD490) values for background opacity and the negative control permeability OD490 values, the mean opacity, and permeability OD490 values for each treatment group were combined in an empirically-derived formula to calculate an in vitro irritancy score (IVIS) for each treatment group as follows:
IVIS = mean opacity value + (15 x mean permeability OD490 value)
The opacity and permeability values were also evaluated independently to determine whether the test item induced corrosivity or severe irritation through only one of the two endpoints.

DECISION CRITERIA:
A test item that induces an IVIS > 55 is defined as a corrosive or severe irritant.
IVIS UN GHS
≤ 3 No Category
> 3 and
≤ 55 No prediction can be made
> 55 Category 1

Irritation parameter:

in vitro irritation score

Run / experiment:

test item

Value:

0.807

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

in vitro irritation score

Run / experiment:

negative control

Value:

1.455

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

in vitro irritation score

Run / experiment:

positive control

Value:

75.65

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

GHS criteria not met

Conclusions:

Under the present test conditions Ukanol FR 70 tested in the in vitro BCOP test method, had an IVIS value of 0.807, which is below the cut-off value of 3 (UN GHS no category) and consequently it is not classified as a severe irritant and is not corrosive according to UN GHS classification.

Executive summary:

The purpose of this study was to determine a possible potency of Ukanol FR 70 of being 'ocular corrosive and severe irritant 'employing an in vitro system.The Bovine Corneal Opacity and Permeability Assay (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, possible damage by the test item was assessed by quantitative measurements of changes in corneal opacity and permeability inisolated corneas from bovine eyes.

Corneal opacity was measured quantitatively as the amount of light transmission through the cornea. Permeability was measured quantitatively as the amount of sodium fluorescein dye that passes across the full thickness of the cornea, as detected in the medium in the posterior chamber.The measurements were used to calculate an in vitro irritancy score (IVIS), which was used to assign an in vitro irritancy hazard classification category for prediction of the in vivo ocular irritation potential of the test item.

Three corneas were used for each treatment group (test item, solvent control and positive control). In a preliminary study, no homogeneous suspension of the test item could be achieved in a 0.9% sodium chloride solution due to the high viscosity of the test item. Hence, the test item was applied directly to the epithelial surface of the cornea. 150 mgUkanol FR 70 (corresponding to 750 µL of the recommended concentration of 20% (w/v) by thetest guideline 437 for non-surfactant solids) were applied to a plastic sheet prior to application to the cornea.The cornea was moistened with 600 µL0.9% NaCl solutionprior to application.0.9% NaCl solution was used as the solvent control and 20% Imidazole in0.9% NaCl solution as the positive control item.

750 µL of the control items as recommended as suitable test volume according to OECD TG 437 were added to completely cover the cornea’s epithelium. The exposure time for the test item and the controls was 240 minutes. The optical density (OD) was measured at a wavelength of 490 nm.The open-chamber method was used.

The acceptance criteria of validity were fulfilled in this test.

Following treatment with Ukanol FR 70 a mean opacity of 0.942±0.738 and a mean permeability value of <0.01compared to the negative control were determined. The calculated IVIS of 0.807±0.590 is below the cut-off value of 3 (UN GHS no category). Hence,the test item did not show severely irritant or corrosive properties and consequently it is not classified as a severe irritant and is not corrosive according to UN GHS classification.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The GHS criteria are not met. The substance is therefore not classified for skin- or eye irritating properties.