2-[[4-(dimethylamino)phenyl]azo]-1,3-dimethyl-1H-imidazolium chloride

Endpoint summary

Description of key information

In vitro skin irritation and corrosion turnkey testing strategy including an OECD 431 and an OECD 439 study; classified

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:

Reported on the 15Apr2015

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:

not specified

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

not specified

Remarks:

Only summary report is available - GLP compliace and QA not specified.

Specific details on test material used for the study:

Name of test substance: Vibracolor ruby red
Test substance No.: 10/0383-3
Batch identification: 0009051093
CAS No.: 77061-58-6

Test system:

human skin model

Remarks:

Human reconstituted epidermis model EpiDerm™

Source species:

human

Cell type:

other: cell type not specified "Human reconstituted epidermis model EpiDerm™"

Cell source:

other: cell source not specified "Human reconstituted epidermis model EpiDerm™"

Source strain:

other: source strain not specified "Human reconstituted epidermis model EpiDerm™"

Vehicle:

unchanged (no vehicle)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

yes, concurrent MTT non-specific colour control

Amount/concentration applied:

Two EpiDerm ™ tissue samples were incubated with 25 μL bulk volume (about 10 mg) of the
undiluted test substance for 3 minutes and 1 hour (corrosion test). Three EpiDerm TM tissue
samples were incubated with 25 μL bulk volume (about 10 mg) of the undiluted test
substance for 1 hour with 42 hours postincubation (irritation test).

Duration of treatment / exposure:

3 minutes and 1 hour (corrosion test).
1 hour with 42 hours postincubation (irritation test).

Duration of post-treatment incubation (if applicable):

42 hours postincubation (irritation test).

Number of replicates:

Duplicate

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

OECD 439In vitro skin irritation test; Final mean variability of tissues after Color Control correction

Value:

45.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

On the basis that this test substance is non-corrosive in TG 431, the result of <50% viability in this test would indicate a skin irritation IN GHS Category 2 classification.

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

OECD 431 In vitro corrosion test; final mean viability of tissues after colour control correction correction

Value:

93.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Not corrosive according to the criteria in this test

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Remarks:

According to TG 439 where a test chemical is found to be non-corrosive in test TG 431 and where the tissue viability after exposure and post-treatment is <50%, the test chemical is considered to be irritant in accordance with UN GHS Category 2.

Conclusions:

In this OECD TG 431 and TG 439 study the tst substance was found to be non-corrosive according to TG 431. According to TG 439, with a tissue viability percentage after colour control correction of 45.5%, the test chemical is irritating.
According to TG 439 where a test chemical is found to be non-corrosive in test TG 431 and where the tissue viability after exposure and post-treatment is <50%, the test chemical is considered to be irritant in accordance with UN GHS Category 2.

Executive summary:

The objective was to assess the potential for corrosive activity and skin irritation of Vibracolor ruby red. Using the currently available methods a single in vitro assay may not always be sufficient to cover the full range of skin irritating/corrosion potential. Therefore, two in vitro assays were part of this in vitro skin irritation and corrosion test strategy: The Skin Corrosion Test (SCT) (OECD TG 431) and Skin Irritation Test (SIT) (OECD TG 439).

The tests were performed according to the test guidelines and as the test chemical is coloured and to avoid colour interferences with the test methods colour controls and freeze-killed control tissues were included in the study as described in the study guidelines.

In the skin corrosion test (TG 431), after 3 minutes the results of the color control (CC) tissues indicate interference due to the color of the test substance (mean value 3.7% of NC). The results of the KC tissues did not indicate an increased MTT reduction. Thus for the test substance the final mean viability is given after CC correction and was 93.9%; a non-corrosive prediction. After a 1 hour exposure period, the results of the color control (CC) tissues indicate interference due to the color of the test substance (mean value 17.2% ofNC).The results of the KG tissues indicate an increased MTT reduction (mean viability 0.2% of NC). Thus for the test substance the final mean viability is given after CC and KC correction and is 75.1%; a non-corrosive prediction.

In the skin irrtation test (TG 439), although red discoloration of the tissues was observed, no extraction of the test substance into the isopropanol was obtained.The results of the KC tissues did not indicate an increased MTT reduction. Thus for the test substance the final mean viability is given without CC and KC correction and is 45.5%. As this is less than the criteria of less than or equal to 50% the results are indicative of skin irritation.

According to TG 439 where a test chemical is found to be non-corrosive in test TG 431 and where the tissue viability after exposure and post-treatment is <50%, the test chemical is considered to be irritant in accordance with UN GHS Category 2.

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:

Reported 17Apr2015

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:

not specified

Qualifier:

according to guideline

Guideline:

other: OECD (2014a) Draft Proposal for a New Test Guideline (EpiOcular™)

Version / remarks:

(2014a) Draft Proposal

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

Test Substance name: Vibracolor ruby red
Test Substance: 10/0383-3
Batch: 0009051093
CAS: 77061-58-6

Species:

other: Two test systems utilised: 1) Isolated corneas from the eyes of freshly slaughtered cattle 2) human reconstructed cornea after a short term topical exposure

Details on test animals or tissues and environmental conditions:

Two test systems utilised:
1) Isolated corneas from the eyes of freshly slaughtered cattle
2) human reconstructed cornea after a short term topical exposure

Vehicle:

other: Both diluted in de-ionized water and undiluted (unchanged; no vehicle)

Amount / concentration applied:

BCOP: Three corneas were treated with 750 μL of 50% and 5% test-substance preparations in deionized water for 10 minutes followed by a 2-hours post-incubation period.
EpiOcular: Two EpiOcular™ tissue samples were incubated with each, 50 μL bulk volume (about 14 mg) of the undiluted test substance or 50 μL of a 5% test-substance preparation for 6 hours followed by an 18-hours post-incubation period.

Duration of treatment / exposure:

BCOP: 10 minutes followed by a 2-hours post-incubation period.
EpiOcular: 6 hours followed by an 18-hours post-incubation period.

Duration of post- treatment incubation (in vitro):

BCOP: 2-hours post-incubation period.
EpiOcular: 18-hours post-incubation period.

Number of animals or in vitro replicates:

BCOP: Three corneas
EpiOcular: Two EpiOcular™ tissue samples

Details on study design:

BCOP: Three corneas were treated with 750 μL of 50% and 5% test-substance preparations in deionized water for 10 minutes followed by a 2-hours post-incubation period.
EpiOcular: Two EpiOcular™ tissue samples were incubated with each, 50 μL bulk volume (about 14 mg) of the undiluted test substance or 50 μL of a 5% test-substance preparation for 6 hours followed by an 18-hours post-incubation period.

Irritation parameter:

cornea opacity score

Run / experiment:

BCOP TEST with test item at 5% in de-ionised water

Value:

1.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Potential for irritation - refer to EIPOCULAR test

Irritation parameter:

cornea opacity score

Run / experiment:

BCOP TEST with test item at 50% in de-ionised water

Value:

0

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Potential for irritation - refer to EIPOCULAR test

Irritation parameter:

in vitro irritation score

Run / experiment:

BCOP TEST with test item at 5% in de-ionised water

Value:

1.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Potential for irritation - refer to EIPOCULAR test

Irritation parameter:

in vitro irritation score

Run / experiment:

BCOP TEST with test item at 50% in de-ionised water

Value:

0

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Potential for irritation - refer to EIPOCULAR test

Irritation parameter:

other: viability values

Run / experiment:

EPIOCULAR TEST - Undiluted test substance

Value:

2.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Irritation parameter:

other: viabilty values

Run / experiment:

EPIOCULAR TEST - 5% test-substance de-ionised in urified water

Value:

4.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Applying the criteria of the OECD 437 fortheassessment of the BCOP test results,theIVISscores ofthe testsubstance of 0.0 (50%testsubstance preparation) or 1.9 (5% test substance preparation) would classify it as a substance that does not cause eye irritation or serious eye damage.However,the Guideline also states,that due to limited accuracy of the BCOP test to correctlyidentifysubstances that do not require classification for eyeirritationor serious eye damage,thistestmethodshould not bethe firstchoice toinitiatea bottom-up approach. Based onthisstatement and the experience ofthe testfacility,testsubstances leading to IVIS <3 are generally examinedin the EpiOculartest as well.In thecurrent case, the EpiOculartestwas positive and thetestsubstance was assessedtobe irritating.

 

Based on the results forBCOPandEpiOcular Testand applying the evaluation criteria describedinsection 3,Vibracolor ruby red showsaneye irritation potentialinthein vitroeye irritation test strategy underthe testconditions chosen.

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Based on the results for BCOP and EpiOcular Test and applying the evaluation criteria described in section 3, Vibracolor ruby red shows an eye irritation potential in the in vitro eye irritation test strategy under the test conditions chosen .

Executive summary:

Based on the results for BCOP and EpiOcular Test and applying the evaluation criteria described in section 3,Vibracolor ruby red shows an eye irritation potential in the in vitro eye irritation test strategy under the test conditions chosen.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)