Potassium chromate

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

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

Adequacy of study:

key study

Study period:

Not applicable

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The EU RAR reports the findings of a number of reports and reviewa; quantification of exposure is not possible.

Data source

Reference

Reference Type:

review article or handbook

Title:

European Union Risk Assessment Report

Author:

European Chemicals Bureau

Year:

2005

Bibliographic source:

3rd Priority List; Volume 53

Materials and methods

Study type:

other: various studies and reports in an EU review

Endpoint addressed:

skin irritation / corrosion

Test guideline

Qualifier:

no guideline available

Deviations:

not applicable

Principles of method if other than guideline:

Review of published reports and reviews of occuaptional exposure

GLP compliance:

no

Remarks:

Not applicable

Test material

Test material information

Constituent 1

Reference substance name:

Chromium trioxide

EC Number:

215-607-8

EC Name:

Chromium trioxide

Cas Number:

1333-82-0

IUPAC Name:

1333-82-0

Constituent 2

Reference substance name:

Sodium chromate

EC Number:

231-889-5

EC Name:

Sodium chromate

Cas Number:

7775-11-3

Molecular formula:

CrH2O4.2Na

IUPAC Name:

disodium dioxido(dioxo)chromium

Constituent 3

Reference substance name:

Sodium dichromate

EC Number:

234-190-3

EC Name:

Sodium dichromate

Cas Number:

10588-01-9

Molecular formula:

Cr2Na2O7

IUPAC Name:

sodium dichromate

Constituent 4

Reference substance name:

Potassium dichromate

EC Number:

231-906-6

EC Name:

Potassium dichromate

Cas Number:

7778-50-9

Molecular formula:

Cr2H2O7.2K

IUPAC Name:

sodium dichromate

Details on test material:

The EU RAR covers the following water soluble hexavalent chromium compounds:

chromium trioxide
sodium chromate
sodium dichromate
ammonium dichromate
potassium dichromate

Method

Subjects:

Various reports are discussed

Route of exposure:

dermal

Reason of exposure:

unintentional, occupational

Exposure assessment:

not specified

Results and discussion

Clinical signs:

Direct accidental contact with very acidic or high temperature solutions of highly water-soluble Cr (VI) compounds has resulted in severe burns to human skin.

Any other information on results incl. tables

In terms of human experience, direct accidental contact with very acidic or high temperature solutions of highly water-soluble Cr (VI) compounds has resulted in severe burns to human skin. It is not clear from the available reports whether intact skin is damaged by single contact with neutral solutions of such compounds. In one patch test study, some volunteers responded to 0.5% aqueous potassium dichromate with mild irritation especially around hair follicles. In workers regularly exposed to highly water-soluble Cr (VI) in solution, chrome ulcers develop after some initial damage to the skin. This has been described for dye workers handling sodium or potassium dichromate solutions and frequently in exposed workers in the chromate production and chrome plating industries. The severity of the ulcer depends upon the frequency and duration of skin contamination. Small papules develop initially, progressing to an ulcer which penetrates gradually to deeper skin layers. Typically, chrome ulcers have a hard circular periphery and a cavity leading to a base covered with exudate or a crust.

Applicant's summary and conclusion

Conclusions:

Water soluble Cr (VI) compounds clearly have the potential to cause skin irritation in humans as shown by a number of reports of accidental
occupational exposure. Chromium (VI) trioxide is corrosive.

Executive summary:

The EU RAR concludes, based on reports of accidental occupational exposure, that the highly water soluble Cr (VI) compounds are skin irritants. Chromium (VI) trioxide is corrosive as a consequence of its low pH and the development of 'chrome ulcers' in workers repeatedly exposed to other salts also indicate the potential for skin corrosivity.