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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
10/7/1984-24/7/1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline-compliant GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: Department of Transportation
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Principles of method if other than guideline:
The study guideline is designed to investigate corrosive effects; the design is similar to OECD 404, however the study was terminated at Day 5 when no signs of corrosion were observed. The results of the study are sufficient to classify the substance for skin irritation accrdoing to EU criteria.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test material is described as a crystalline solid and was used as a mixture of material obtained from six different sources.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Summit View Farm, NJ, USA
- Age at study initiation: 10-12 weeks
- Weight at study initiation: not reported
- Housing: Individual in wire mesh cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: At least 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/-4
- Humidity (%): 50 +/- 15
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 10/7/84 To: 24/7/84

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
physiological saline
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g in 0.5 ml saline
- Concentration (if solution): 1 g/ml


VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 ml saline
- Concentration (if solution):
- Lot/batch no. (if required):
- Purity:
Duration of treatment / exposure:
4 hours
Observation period:
5 days
Number of animals:
Six
Details on study design:
TEST SITE
- Area of exposure: 1 square inch
- % coverage:
- Type of wrap if used: Saran


REMOVAL OF TEST SUBSTANCE
- Washing (if done): If required
- Time after start of exposure: 4 hours


SCORING SYSTEM: Draize
TEST SITE
- Area of exposure: 1inch square
- % coverage: -
- Type of wrap if used: Saran


REMOVAL OF TEST SUBSTANCE
- Washing (if done): saline
- Time after start of exposure: 4 hours


SCORING SYSTEM: Draize

Results and discussion

In vivo

Irritant / corrosive response data:
See below
Other effects:
Orange staining of the application site was seen in animals exposed to the moistened test material. Focal necrosis was additionally observed in one animal at the 48-hour observation only (moistened test material).

Any other information on results incl. tables

No dermal reactions were seen in animals treated with the control patches. With the dry test material, signs of irritation were limited to moderate erythema in two animals which declied in severity, but were still present at the end of the study period. Orange staining of the application site was seen in animals exposed to the moistened test material. Signs of irritation were seen from 48 hours in animals exposed to the moistened test material. Grade 2 erythema was seen in all animals from 48 hours and persisted to study termination; Grade 4 erythema was seen in one animal at 48 hours only. Grade 1 -3 oedema was observed in five animals; findings declined in severity and were not apparent at study termination at 120 hours. Focal necrosis was additionally apparent in one animal at 48 hours but not at later time points, demonstrating rapid reversibility.

Mean scores for skin irritation

Application

Observation

4h

48h

72h

96h

120h

Dry

Erythema

0.00

0.67

0.67

0.50

0.30

Oedema

0.00

0.00

0.00

0.00

0.00

Moistened

Erythema

0.00

2.33

2.00

2.00

2.00

Oedema

0.00

1.50

0.67

0.33

0.00

Control

Erythema

0.00

0.00

0.00

0.00

0.00

Oedema

0.00

0.00

0.00

0.00

0.00

Applicant's summary and conclusion

Interpretation of results:
irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Sodium dichromate was found to be a skin irritant under the conditions of this study according to EU criteria, based on the mean scores for erythema and the non-reversibility of the effects within the time-frame of the study.
Executive summary:

The dermal irritancy of sodium dichromate was investigated in the rabbit; the test material was administered dry or mositened with saline. Relatively mild local dermal reactions were seen following applictaion of the dry test material. Orange staining of the application site and local irritation (erythema and oedema) were seen following application of the moistened test material; irritation was declining in severity but was not reversible within the 120-hour study period. T here was no evidence of corrosivity, however the test material was shown to be a skin irritant.

Although the study design (in respect of observation time points) is not completely in line with the recommendations of OECD 404, it can be deduced from the results of this study that sodium dichromate meets the criteria for classification as a skin irritant according to EC criteria due to the severity of erythema and the non-reversibility of the dermal reactions within the study period.

The results suggest that the irritancy of the test material is a consequence of its low pH when in solution.