Potassium dichromate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-standard exposure period of 24 hour, reliability also limited by the level of mortality

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Principles of method if other than guideline:

Similar to OECD 404 however a 24-hour application period was used.

GLP compliance:

no

Remarks:

Pre-dates GLP

Test material

Test material information

Constituent 1

Reference substance name:

Sodium chromate

EC Number:

231-889-5

EC Name:

Sodium chromate

Cas Number:

7775-11-3

IUPAC Name:

disodium dioxido(dioxo)chromium

Constituent 2

Reference substance name:

Sodium dichromate

EC Number:

234-190-3

EC Name:

Sodium dichromate

Cas Number:

10588-01-9

Constituent 3

Reference substance name:

Potassium dichromate

EC Number:

231-906-6

EC Name:

Potassium dichromate

Cas Number:

7778-50-9

Molecular formula:

K2Cr2O7

IUPAC Name:

sodium dichromate

Details on test material:

The study was perfomed using the water-soluble Cr (VI) compounds sodium chromate, sdoium dichromate, potassium dichromate and ammonium dichromate (results not reported)

Test animals

Species:

rabbit

Strain:

New Zealand White

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

physiological saline

Controls:

other: Concurrent control patch

Duration of treatment / exposure:

0.5 g of each of the test materials was mositened with 0.5 ml physiological saline and applied for 24 hours under a gauze patch.

Observation period:

72 hours

Number of animals:

Six animals were used for each of the test substances

Results and discussion

In vivo

Irritant / corrosive response data:

See below

Other effects:

Evidence of systemic toxicity was noted in all animals.

Any other information on results incl. tables

Sodium chromate

Four rabbits were found dead and one was killed in extremis. Signs of toxicity included hyperkinesia, hypokinesia, immobile hindlimbs and hypothermia. Dermal irritation (very slight to well-defined erythema; very slight to moderate oedema), was seen in all animals, as detailed below. Signs declined slightly in severity, but were still apparent at termination.

Scores for dermal irritation:

Observation	1h	24h	48h	72h	Mean (48-72 hours)	4 days	5 days
Erythema	2,1,1,1 [1.25]	2,1,1 [1.33]	1,1,1 [1.00]	1,1,1 [1.00]	1.11	1,1 [1.0]	1 [1]
Oedema	3,3,3,1 [2.50]	3,3,1 [2.33]	3,3,2 [2.67]	3,3,2 [2.67]	2.56	2,2 [2.0]	2 [2]
Mortality	2/6	3/6	3/6	3/6	-	4/6	5/6

Sodium dichromate

Four rabbits were found dead and two were killed in extremis. Signs of toxicity included sedation, ataxia, hypothermia, incontinence, severe diarrhoea and clonic convulsions. Dermal irritation (very slight erythema and oedema) were seen in surviving animals, as detailed below. Bright yellow discoloration was additionally observed at the application site.

Scores for dermal irritation:

Observation	1h	24h	48h	72h	Mean (48-72 hours)	4 days	5 days
Erythema	1,1 [1.0]	-	-	-	-	-	-
Oedema	1,1 [1.0]	-	-	-	-	-	-
Mortality	4/6	6/6	6/6	6/6	-	6/6	6/6

Potassium dichromate

One rabbit was found dead and three were killed in extremis. Signs of toxicity included hypokinesia, ataxia, slight diarrhoea, immobile hindlimbs, sedation and hypothermia. Dermal irritation (very slight to moderate erythema; very slight to severe oedema), was seen in all animals, as detailed below. Signs declined slightly in severity, but were still apparent at termination.

Scores for dermal irritation:

Observation	1h	24h	48h	72h	Mean (48-72 hours)	4 days
Erythema	1,1,1,1,1,1 [1.00]	1,1,1 [1.00]	1,3 [2.0]	1,3 [2.0]	1.67	1,2 [1.5]
Oedema	3,2,1,3,3,3 [2.50]	0,1,3 [1.33]	1,4 [2.5]	1,4 [2.5]	2.11	1,4 [2.5]
Mortality	-	3/6	4/6	4/6	-	4/6

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information No conclusion Criteria used for interpretation of results: expert judgment

Conclusions:

Based on the mean scores for dermal irritation in this study and the absence of reversibility, it is concluded that sodium chromate and potassium dichromate are likley to be skin irritants. It is assumed that sodium dichromate is also a skin irritant, based on read-across from these two compounds.

Executive summary:

The dermal irritation of sodium chromate, sodium dichromate and potassium dichromate was investigated in the rabbit (6/group). 0.5 g of each of the test substances was moistened with 0.5 ml physiological saline and applied under a gauze patch. Mortality and signs of systemic toxicity were seen in each group of animals. Signs of irritation were also seen, but there was no evidence of corrosivity. The application time of 24 hours exceeds the standard 4 -hour period, however it is considered likely that the compounds would be classified as skin irritants based on the results of a guideline-compliant test.