N'-(1,3-dimethylbutylidene)-3-hydroxy-2-naphthohydrazide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 03 - 06, 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): BMH
- Physical state: White crystal
- Storage condition of test material: In the refrigerator in the dark
- Stability under storage conditions: Stable
- Stability in water: No
- Stability in ethanol: At least 24 h
- Solubility in water/ethanol: Unknown

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Kisslegg, Germany.
- Age at study initiation: see attached background material
- Weight at study initiation: see attached background material
- Housing: Individually housed in labelled cages with perforated floors (Scanbur, Denmark) and equipped with an automatic drinking system (ITL, Bergen, The Netherlands).
- Diet (e.g. ad libitum): Standard laboratory rabbit diet (Charles River Breeding and Maintenance Diet for Rabbits, Altromin, Germany) approx. 100 g. per day. Certificates of analysis were examined and retained in the NOTOX archives. In addition, hay (BMI, Helmond, the Netherlands) was provided twice a week.
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: The acclimatization period was at least 5 days before the start of treatment under laboratory conditions.

A health inspection was performed prior to treatment, to ensure that the animals were in a good state of health. Special attention was paid to the skin to be treated, which was intact and free from abnormalities.

Results of analysis for diet (nutrients and contaminants), and water were assessed and did not reveal any findings that were considered to have affected the study integrity. All certificates and results of analysis are retained in the NOTOX archives.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: shaved approx. 24 hours before treatment

Vehicle:

other: The test substance was moistened with 0.5 mL of ethanol.

Controls:

other: Adjacent areas of the untreated skin of each animal served as controls.

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3 males

Details on study design:

TEST SUBSTANCE PREPARATION
The powdery test substance was moistened with ethanol, immediately before application, to ensure close contact with the animal's skin.

TEST SITE
Approximately 24 hours before treatment, the dorsal fur was clipped with electric clippers, exposing an area of approximately 150 square centimeters (10x15 cm²). Whenever considered necessary the treated skin areas were re-clipped at least 3 hours before the observations, to facilitate scoring.

The test substance was applied to the skin of one flank, using a metalline patch# of 2x3 cm. The patch was mounted on Micropore tape#, which was wrapped around the abdomen and secured with Coban elastic bandage#.

REMOVAL OF TEST SUBSTANCE
Four hours after the application, the dressing was removed and the skin cleaned of residual test substance using tap water.
#. Suppliers: Lohmann GmbH, Neuwied, Germany (Metalline) and 3M, St. Paul, Minnesota, U.S.A. (Micropore and Coban).

OBSERVATIONS
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to application).
- Necropsy: No necropsy was performed according to protocol.
- Irritation:
The skin reactions were assessed at approximately 1, 24, 48 and 72 hours after the removal of the dressings and test substance. The irritation scores and a description of all other (local) effects were recorded.

SCORING SYSTEM:
The irritation was assessed according to the following numerical scoring system. At each observation, the highest scores given were recorded:

Erythema and eschar formation:
0: No erythema
1: Very slight erythema (barely perceptible)
2: Well-defined erythema
3: Moderate to severe erythema
4: Severe erythema (beet redness) *
*. Where signs of necrosis or corrosion (injuries in depth) prevent erythema scoring, the maximum grade for erythema (= 4) was given.

Oedema formation:
0: No oedema
1; Very slight oedema (barely perceptible)
2: Slight oedema (edges of area well-defined by definite raising)
3: Moderate oedema (raised approximately 1 millimeter)
4: Severe oedema (raised more than 1 millimeter and extending beyond the area of exposure)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #1, #2 and #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Following exposure, yellow staining of the treated skin-area was noted after removal of the test substance.

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #1, #2 and #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

other: Following exposure, yellow staining of the treated skin-area was noted after removal of the test substance.

Irritant / corrosive response data:

Four hours exposure to 0.5 g of BMH resulted in very slight erythema in the treated skin-area of one of the three rabbits, after 1 hour only. No oedema was noted in any of the animals. There was no evidence of a corrosive effect on the skin.

Tables containing individual and mean irritation scores are specified in the table in the attached background material.

Other effects:

No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

A primary skin irritation/corrosion study with BMH in the rabbit (4-hour semi-occlusive application, 3 males) was conducted according to OECD 404 and GLP guidelines. BMH does not have to be classified and has no obligatory labelling requirement for skin irritation.