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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
from 5 March 2013 to 18 June 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name as mentioned in the study report: cerium ammonium nitrate

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Leicestershire, UK
- Age at study initiation: 12-20 weeks
- Weight at study initiation: 2.6 kg
- Housing: suspended cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23°C
- Humidity (%): 30-70%
- Air changes (per hr): at least 15 changes per hour
- Photoperiod (hrs dark / hrs light): 12h light (6-18h); 12h dark (18-6h)

IN-LIFE DATES: From: 5 March 2013 To: 5 March 2013

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
water
Controls:
other: not needed
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g of the test item was used as supplied, moistened sufficiently with 0.5 mL of distilled water to achieve a paste.


Duration of treatment / exposure:
3 minutes
1 hour
4 hours
Observation period:
immediately after removal and approximately 1h later
Number of animals:
one male
Details on study design:
TEST SITE
- Area of exposure: 3 suitable sites on the back of the rabbit
- Type of wrap if used: 2.5 cm x 2.5 cm cotton gauze patch, secured with a strip of surgical adhesive tape. The trunk was wrapped in an elasticated corset for the duration of the exposure period.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): residual test item was removed by gentle swabbing with cotton wool soaked in distilled water
- Time after start of exposure: immediately

SCORING SYSTEM:
Erythema and eschar formation:
No erythema - 0
Very slight erythema (barely perceptible) - 1
Well-defined erythema - 2
Moderate to severe erythema - 3
Severe erythema (beff redness) to eschar formation preventing grading of erythema - 4

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

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
overall irritation score
Remarks:
3 min exposure
Basis:
animal #1
Time point:
other: immediately and 1 hour
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Irritation parameter:
overall irritation score
Remarks:
1 hour exposure
Basis:
animal #1
Time point:
other: immediately and 1 hour
Score:
0
Max. score:
4
Reversibility:
other: not applicable
Irritation parameter:
erythema score
Remarks:
4 hour exposure
Basis:
animal #1
Time point:
other: immediately
Score:
2
Max. score:
4
Reversibility:
not reversible
Remarks on result:
other: purple/green colored dermal necrosis, animal was killed for humane reasons after the observation
Irritation parameter:
edema score
Remarks:
4 hour exposure
Basis:
animal #1
Time point:
other: immediately
Score:
2
Max. score:
4
Reversibility:
not reversible
Remarks on result:
other: animal killed for humane reasons after the observation
Irritant / corrosive response data:
3-Minute and 1-Hour semi-occluded applications of the test item to the intact skin of one rabbit produced no evidence of skin irritation.

A single 4-Hour semi-occluded application of the test item to the intact skin of one rabbit produced: Well-defined erythema and slight oedema were noted at the test site immediately after patch removal. Purple/green colored dermal necrosis, approximately 2 cm x 2 cm in size and extending approximately 1 cm below and 1 cm to the rear of the test site, was also noted at the observation.

The skin reactions noted were considered to be irreversible and indicative of full thickness tissue destruction, therefore the animal was killed for humane reasons immediately after the observation, in accordance with Company policy and current UK Home Office guidelines.

Applicant's summary and conclusion

Interpretation of results:
Category 1C (corrosive) based on GHS criteria
Conclusions:
The test item was classified as corrosive to rabbit skin (based on one animal only). The test item was classified as Category 1C according to the CLP Regulation 1272/2008.