[No public or meaningful name is available]

Endpoint summary

Description of key information

Skin irritation

Although the precise tissue viability could not be obtained, the relative mean viability of the test material treated tissues was 133.9%, well above 50% that would require classification for skin irritation.  

Eye irritation

Based on the results of the BCOP test, the test material score of 0.2 indicates it is not an eye irritant.

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:

07 February 2018 to 03 June 2020

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

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

-Purity: >95% (nominal); UVCB
-Description: Amber Liquid
- Storage: room temperature, in the dark

Test system:

human skin model

Source species:

human

Cell type:

other: reconstructed human epidermis tissues

Cell source:

other: Not specified

Vehicle:

unchanged (no vehicle)

Details on test system:

Triplicate tissues were treated with the test material for an exposure period of 15 minutes. At the end of the exposure period each tissue was rinsed before incubating for 42 hours. The test material was found to have the potential to directly reduce MTT and therefore, as a precaution, additional non-viable tissues were incorporated into the testing for correction purposes. The test material was found to cause color interference with the MTT endpoint therefore, additional tissues were incorporated into the testing to correct for this. A third set of controls was included, comprising non-viable tissues, to prevent a double correction from a colored test item that also reduces MTT. At the end of the post exposure incubation period each tissue was taken for MTT-loading. The maintenance medium from beneath each tissue was transferred to pre labeled micro tubes and stored in a freezer for possible inflammatory mediator IL-1α determination. After MTT-loading a total biopsy of each epidermis was made and placed into micro tubes containing acidified isopropanol for extraction of formazan crystals out of the MTT loaded tissues.

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

Control samples:

other: Negative Control: Dulbecco’s Phosphate Buffered Saline (DPBS) with Ca++ and Mg++ and Positive Control: Sodium Dodecyl Sulphate (SDS)

Amount/concentration applied:

10 µL (26.3 µL/cm2) of the test item was applied to the epidermis surface.

Duration of treatment / exposure:

Triplicate tissues were treated with the test item for an exposure period of 15 minutes

Duration of post-treatment incubation (if applicable):

At the end of the exposure period each tissue was rinsed before incubating for 42 hours.

Number of replicates:

Three

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

using the EPISKINTM reconstructed human epidermis model after a treatment period of 15 minutes followed by a post exposure incubation period of 42 hours

Value:

133.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Test for Direct MTT Reduction

The MTT solution containing the test item turned purple which indicated that the test material directly reduced MTT. Therefore, an additional procedure using water-killed tissues was performed. However, the results obtained showed that no effects on OD₅₇₀values that indicated the test material was totally rinsed off with no residual test material remained on or in the tissues. It was therefore considered unnecessary to use the results of the water-killed tissues for quantitative correction of results.

Test Item, Positive Control Item and Negative Control Item

The relative mean viability of the test material treated tissues was 133.9% (>50%) after a 15‑minute exposure period and 42‑hour post‑exposure incubation period.

Assessment of Color Interference with the MTT endpoint

The test item was found to produce a colored solution which might interfere with the MTT endpoint. Therefore, color correction tissues were incorporated into the test to correct for this possibility. These tissues were treated identically to the tissues of the main test with the exception of being placed into assay medium for 3 hours post exposure instead of MTT. Three tissues were dosed with the test material and three remained untreated to act as negative controls.

Quality Criteria

The relative mean viability for tissues treated with 5% (w/v) SDS aqueous solution (positive control) was 2.7% relative to the negative control treated tissues and the standard deviation value of the viability was 0.6% (≤18%). The positive control acceptance criteria were therefore satisfied.

The mean OD₅₇₀for the negative control (DPBS) treated tissues was 0.736, within the range of 0.6 - 1.5 and the standard deviation value of the viability was 1.2% (≤18%). The negative control acceptance criteria were therefore satisfied.

The standard deviation calculated from individual tissue viabilities of the three identically test item treated tissues was 7.1% (≤18%). The test item acceptance criterion was therefore satisfied.

However, the interference of the remained test item on the viable tissues with the MTT endpoint could not be corrected because the amber colored test material adhered to remained on the viable tissue surfaces, but not on the non-viable tissue surfaces after rinsing and the precise tissue viability could not be obtained.

Interpretation of results:

GHS criteria not met

Conclusions:

Although the precise tissue viability could not be obtained, the relative mean viability of the test material treated tissues was 133.9%, well above 50% that would require classification for skin irritation.

Executive summary:

The test material, Fatty acids, C₁₈-unsatd., dimers, compds, with 4,5-dihydro-2-nortall-oil alkyl-1H-imidazole-1-ethanol and tall-oil fatty acids, was amber color that interfered with the MTT endpoint of this assay. Additionally the test item adhered to and remained on the culture surfaces of the viable tissues, but not on the non-viable tissues after rinsing. Therefore, the interference of the remained amber color test material on the viable tissues with the MTT endpoint could not be corrected with non-viable tissues. Although the precise tissue viability could not be obtained, the relative mean viability of the test material treated tissues was 133.9%, well above 50% that would require classification for skin irritation. In addition, the score of the test material in the BCOP assay was 0.2, well below the score of 3 that would require classification for eye irritation. The undiluted test material had no signs of local skin irritation to mouse ears in the LLNA in mice. The acute oral toxicity study of the test material showed no clinical signs of toxicity, no gross lesions at necropsy, and acceptable weight gain by all animals dosed by gavage at 2000 mg/kg. Therefore, the existing data provide sufficient weight of evidence to justify not classifying the test item for dermal irritation in accordance to Regulation (EC) No. 1272/2008 Classification, Labelling and Packaging of Substances and Mixtures (EU CLP) and United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 February 2018 to 10 September 2018

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 Ocular Corrosives and Severe Irritants)

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

Specific details on test material used for the study:

Purity: >95% (nominal); a substance of Unknown or Variable composition, Complex reaction products or Biological materials (UVCB)
Physical state/Appearance: Amber Liquid

Species:

cattle

Strain:

not specified

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 prepared immediately on arrival.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

0.75 mL of the test material or control items were applied to the appropriate corneas

Duration of treatment / exposure:

Each holder was incubated, anterior chamber uppermost, at 32 ± 1 ºC for 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
The cornea from each selected eye was removed leaving a 2 to 3 mm rim of sclera to facilitate handling, and 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 chambers of each BCOP holder were filled with complete Eagle’s Minimum Essential Medium (EMEM) without phenol red, plugged and 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 and a pre treatment opacity reading was taken for each cornea using a calibrated opacitometer. The average opacity for all corneas was calculated.

Treatment of Corneas
The EMEM was removed from the anterior chamber of the BCOP holder and the test item or control items were applied to the appropriate corneas and each holder was incubated 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 with fresh complete EMEM containing phenol red before a final rinse with complete EMEM without phenol red. The chamber was then 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 at 32 ± 1 ºC for 120 minutes. After incubation, 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 was removed and replaced with 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 software.

Irritation parameter:

in vitro irritation score

Run / experiment:

10 minute exposure period and 120 minutes post exposure

Value:

0.2

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the BCOP test, the test material score of 0.2 indicates it is not an eye irritant.

Executive summary:

In a study performed to the standardized guidelines OECD 437 and EU Test Method B.47., under GLP conditions, the test material is not an irritant to eye, not requiring classification.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available