Methylium, triphenyl-, tetrakis(pentafluorophenyl)borate(1-).

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 - 24 October 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

472-690-5

EC Name:

-

Cas Number:

136040-19-2

Molecular formula:

C24BF20.C19H15

IUPAC Name:

Methylium, triphenyl-, tetrakis(pentafluorophenyl)borate(1-).

Test material form:

solid: particulate/powder

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan, Horst, The Netherlands
- Age at study initiation: at least 6 weeks old
- Weight at study initiation: at least 1 kg
- Housing: cage with perforated floor
- Diet (e.g. ad libitum): 100 g pelleted diet per day
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days before start of treatment under lab conditions

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.4 - 23.2 C
- Humidity (%): 42-73%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

other: corn oil

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g

VEHICLE
- Amount(s) applied (volume or weight with unit): since the powdery test substance is not stable in water, the substance was moistened with 0.5 ml corn oil immediately before application to ensure close contact with the animal's skin.

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). Since evidence of full thickness destruction of the skin (scar tissue) was obtained, the two other animals were not treated.

Details on study design:

TEST SITE
- Area of exposure: 2x3 cm = 6 cm2
- % coverage: 100%
- Type of wrap if used: metalline patch mounted on Micropore tape, wrapped around the abdomen and secured with Coban elastic bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): skin was cleaned of residual test substance using corn oil.
- Time after start of exposure: 4 hours

OBSERVATION TIME POINTS
Mortality twice daily, toxicity at least once daily, body weight at day of treatment and termination, irritation at 1, 24, 48 and 72 hours and 7 and 14 days after the removal of the dressings and test substance.

SCORING SYSTEM:
- Method of calculation: erythema 0 - 4, oedema 0 - 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Remarks:

mean

Basis:

animal #1

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Results 2

Irritation parameter:

edema score

Remarks:

mean

Basis:

animal #1

Time point:

24/48/72 h

Score:

2.67

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Irritant / corrosive response data:

1 hour after exposure: erythema 2, oedema 2, yellow staining of the skin by the test substance
24 hours after exposure: erythema 4, oedema 3
48 hours after exposure: erythema 4, oedema 3, reduced flexibility of the skin
72 hours after exposure: erythema 4, oedema 2, reduced flexibility of the skin and superficial brown discolouration (sign of necrosis)
7 days after exposure: erythema 4, oedema could not be scored due to fissuring of the skin
14 days after exposure: erythema 1, oedema 1, bald skin, noticeably white skin (scar tissue), scaliness

Other effects:

No symptoms of toxicity were observed, nor mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

Category 1C (corrosive) based on GHS criteria

Conclusions:

Evidence of full thickness destruction of the skin (scar tissue) was observed during the observation period, indicating that corrosion of the skin had occurred by dermal application of the test substance to the intact rabbit skin. Based on these results, according to CLP, the substance should be classified as skin corrosive category 1C.