1H-Benzimidazole-5,7-disulfonic acid, 2,2'-(1,4-phenylene)bis-, sodium salt (1:2)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996-03-18 to 1996-03-26

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP study reliable with restrictions Deviations from EU method B.4 (2008): - according to the guideline when responses such as scaling persist to the end of the 14-day observation period, the test substance should be considered an irritant. In this study scaling was observed at 72 hours and on day 7 of the study. After day 7 the observation of the animals was terminated. The study should have been continued at least until day 14 in order to see, if the scaling effect was reversible. Since this did not happen the study has limited reliablity for classification of the test material. - in addition to the observation of irritation, all local toxic effects, such as defatting of the skin, and any systemic adverse effects (e.g. effects on clinical signs of toxicity and body weight), should be fully described and recorded. The systemic adverse effects were not recorded in the study report. - the age of the animals and the animal weights at the conclusion of the test were missing in the study report.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

1992

Deviations:

yes

Remarks:

please refer to "Rationale for reliability incl. deficiencies" above

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1992-07-17

Deviations:

yes

Remarks:

Rationale for reliability incl. deficiencies" above

GLP compliance:

yes (incl. QA statement)

Remarks:

Data of inspection March 1996

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

429-750-0

EC Name:

-

Cas Number:

180898-37-7

Molecular formula:

C20H12N4O12S4.2Na

IUPAC Name:

disodium dihydrogen 2-[4-(5,7-disulfonato-1H-1,3-benzodiazol-2-yl)phenyl]-1H-1,3-benzodiazole-5,7-disulfonate

Details on test material:

- CAS name: 1H-Benzimidazole-4,6-disulfonic acid-2,2´-(1,4-diphenylene) bis, disodium salt
- Molecular formula: C20H12N4O12S4Na2
- Molecular weight: 674g/mol
- physical state: solid

Test animals

Species:

rabbit

Strain:

other: stock Mol:Russian

Details on test animals or test system and environmental conditions:

TEST ANIMALS - SPF albino rabbits
- Source: MØllegaard Breeding and Research Centre A/S, Ejby, DK-4623 Lille Skensved
- Weight at study initiation: 2.0 - 2.1 kg
- Housing: during a pre-period of at least one week and throughout the experiment the rabbits were caged individually in PPO/HIPS (Noryl®) cages (floor area: 2576 cm^2) with perforated floor.
- Diet (ad libitum): a pelleted complete rabbit diet "Altromin 2123" from Chr. Petersen, DK-4100 Ringsted
- Water (ad libitum): domestic quality drinking water acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth
- Acclimation period: a per-period of at least one week

ENVIRONMENTAL CONDITIONS
- Temperature: 21°C ± 3°C
- Relative humidity: 55% ± 15%
- Air changes: 10 times/hour
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):0.5 g of HR 96/N0002 moistened with distilled water

Duration of treatment / exposure:

4 hours

Observation period:

1, 24, 48 and 72 hours as well as 7 days after termination of exposure

Number of animals:

4 female rabbits

Details on study design:

TEST SITE
- Area of exposure and type of wrap used: the day before the experiment was started the rabbits were weighed and an area of 10 X 10 cm on the back was clipped as closely as possible with an electric clipper.
On the experimental day the rabbits were physically restrained on a test table, and the clipped area was divided into four test sites: two anterior located test sites and two posterior located test sites. To each of four gauze patches (2.5 X 2.5 cm) HR 96/N00002 moistened with the vehicle was applied. Indentically 0.5 mL of three other test articles were applied to gauze patches (please refer for results on these three test materials to Section 7.3.1 Skin irritation / corrosion: s_Aarup_1997). The patches were placed on the appropriate test site on the back of each rabbit. The gauze patches were secured with 2.5 cm wide adhesive tape and fixed with Scanpor tape (5 cm width). Thereafter Nobifix (6 cm width) was loosely wound round the trunk. The application schedule of the four test articles are given in the field "Any other information on materials and methods incl. tables" below.

REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: after the exposure time of 4 hours
- Washing: the tape and patches were removed and the treated skin was cleaned with lukewarm water.

SCORING SYSTEM: according to the Draize scale

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #1

Time point:

other: 24, 48 and 72 hours

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: However, at the examination 72 hours after termination of exposure the test site of the rabbit showed slight scale formation. On day 7 few scales were still present but the skin of the test site was intact.

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #1

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #2

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Remarks on result:

other: At the examination 72 hours after termination of exposure the test site of the rabbit showed slight scale formation. On day 7 few scales were still present but the skin of the test site was intact.

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #2

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Results 5

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #3

Time point:

other: 24, 48 and 72 hours

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: However, at the examination 72 hours after termination of exposure the test site of the rabbit showed slight scale formation. On day 7 few scales were still present but the skin of the test site was intact.

Results 6

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #3

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Results 7

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #4

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Remarks on result:

other: At the examination 72 hours after termination of exposure the test site of the rabbit showed slight scale formation. On day 7 few scales were still present but the skin of the test site was intact.

Results 8

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #4

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Irritant / corrosive response data:

Note: the results given below refer only to HR 96/N00002. For the results on the other applied test materials please refer to Section 7.3.1 Skin irritation / corrosion: s_Aarup_1997.

One hour after termination of exposure the test sites of the four rabbits showed slight skin erythema (grade 1). During the rest of the observation period slight erythema (grade 1) was observed among two rabbits. No oedema was observed in any of the rabbits.
At the examination 72 hours after termination of exposure the test sites of the four rabbits showed slight scale formation.
On day 7 few scales were still present but the skin of the test sites was intact.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In conclusion the test materialis considered to be not irritating to the skin.
According to 67/548/EC and subsequent regulations, the test substance is not classified as a skin irritant.
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test substance is not classified as skin irritant.

Executive summary:

According to the outcome of the test, effects observed in 2 of 3 animals on erythema (score ≤1) are fully reversible within 7 days. Hence, no classification is required. However, 72 hours after termination of exposure the test site of the rabbit showed slight scale formation. On day 7 (test end) few scales were still present but the skin of the test site was intact.

According to regulation (EC) 1272/2008:“...inflammation persists to the end of the observation period in 2 or more test animals, taking into consideration alopecia (limited area), hyperkeratosis, hyperplasia and scaling, then a material shall be considered to be an irritant.”Nevertheless, according to the OECD guideline 404 the observation period should be up to 14 days. Since the observation period in this study was chosen to be 7 days only and the fact that only few scales were still present after 7 days but the skin of the test site was already intact, it can safely be assumed that all effects observed would be reversible within 14 days.