Potassium chromate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Study period:

From 1954 to 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The EU RAR summarises the results of a number of fish acute studies which, individually, have limitations regarding study design and reliabilty. However the results of these studies when taken as a whole, provide an adequate assessment of acute toxicity to fish. The data are considered to fulfil the criteria laid down in Annex XI to Regulation 1907/2006: adequate for classification and labelling, adequate coverage of key parameters (lethality), exposure duration comparable or longer that Article 13(3) methods ( 96 hours), adequate documentation provided: EU RAR, of which parts have been copied to this endpoint record. Reliability for endpoint also increased based on test results from several species.

Data source

Reference

Reference Type:

review article or handbook

Title:

European Union Risk Assessment Report: chromium trioxide, sodium chromate, sodium dichromate, ammonium dichromate and potassium dichromate

Author:

European Chemicals Bureau

Year:

2005

Bibliographic source:

3rd. Priority List; Volume 53

Materials and methods

Test guideline

Qualifier:

no guideline followed

Guideline:

other: range of studies included

Deviations:

not applicable

Principles of method if other than guideline:

Several studies, collectively, provide a weight-of-evidence to address the acute toxicity endpoint. The methods include the appropriate endpoints (lethality and sublethal effects) and duration (equal to 96 hours exposure). Results from more species than recommended have been reported and hence provide an adequate representation of acute toxicity to fish.

GLP compliance:

no

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

IUPAC Name:

disodium dioxido(dioxo)chromium

Constituent 3

Reference substance name:

Potassium chromate

EC Number:

232-140-5

EC Name:

Potassium chromate

Cas Number:

7789-00-6

Molecular formula:

CrH2O4.2K

IUPAC Name:

dipotassium dioxochromiumbis(olate)

Constituent 4

Reference substance name:

Sodium dichromate

EC Number:

234-190-3

EC Name:

Sodium dichromate

Cas Number:

10588-01-9

Constituent 5

Reference substance name:

Potassium dichromate

EC Number:

231-906-6

EC Name:

Potassium dichromate

Cas Number:

7778-50-9

Constituent 6

Reference substance name:

Ammonium dichromate

EC Number:

232-143-1

EC Name:

Ammonium dichromate

IUPAC Name:

Ammonium dichromate

Details on test material:

For some fish species, toxicity data are available for more than one of the chromium (VI) compounds included in this assessment. The available information indicates that, when expressed on a total chromium concentration, there are no significant differences between the toxicity of sodium chromate, sodium dichromate and potassium dichromate (allowing for differences in water properties). This is as would be expected if the equilibria between the chromate and dichromate anions are established in the test medium. Little information is available for ammonium dichromate and chromic acid, but it would be expected that their toxicity would be similar to that of the other chromates/dichromates, when expressed on a total chromium concentration basis.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
See Test material identity above

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Various sampling procedures based on multiple studies

Test solutions

Vehicle:

no

Details on test solutions:

various test media prepared based on multiple studies in freshwater and salt water.

Test organisms

Test organisms (species):

other: Range of species tested

Details on test organisms:

Range of species tested

Study design

Test type:

other: Range of test designs used

Water media type:

freshwater

Limit test:

no

Remarks on exposure duration:

Range used from several studies

Post exposure observation period:

None reported

Test conditions

Hardness:

Range used from several studies

Test temperature:

Range used from several studies

pH:

Range used from several studies

Dissolved oxygen:

Range used from several studies

Salinity:

Range used from several studies

Nominal and measured concentrations:

Range used from several studies

Details on test conditions:

Range used from several studies

Reference substance (positive control):

not specified

Results and discussion

Details on results:

See any other information below.

Any other information on results incl. tables

Sublethal observations / clinical signs:

The results of the acute fish toxicity studies evaluated in the EU RAR are summarised below:

Species	Endpoint	Value (mg/l)	Reference
Freshwater
Brachydanio rerio	96-hour LC50	58.5	Bellavere and Gorbi (1981)
Carrasius auratus	96-hour LC50	37.5	Pickering and Henderson (1966)
Channa punctatus	96-hour LC50	45.2	Saxena and Parashari (1983)
Colisa fasciatus	96-hour LC50	20.8c	Srivastava et al. (1979)
Ictalurus punctatus	24-hour LC50	58	Cairns Jr. et al (1978)
Lebistes reticulatus	96-hour TLm	30	Pickering and Henderson (1966)
Lepomis macrochirus	96-hour LC50 48-hour TLm 96-hour LC50	110 213a 120b	Trama and Benoit (1960) Turnbull et al. (1954) Cairns Jr. and Scheier (1958)
Morone saxitalis	96-hour LC50	28b	Palawski et al. (1985)
Notemigonus crysoleucas	96-hour LC50	55	Hartwell et al. (1989)
Oncorhynchus mykiss	96-hour LC50	63.6 69a 13d	Brown et al. (1985) Benoit (1976) Van Der Putte et al (1981b)
Pimephales promelas	96-hour TLm 96-hour LC50 96-hour TLm	17.6 33.2a 45.6b	Pickering and Henderson (1966) Benoit (1976) Pickering and Henderson (1966)
Salvelinus fontinalis	96-hour LC50	59	Benoit (1976)
Saltwater
Alburnus alburnus*	96-hour LC50	84.8	Lindén et al. (1979)
Chelon labrosus	48-hour LC50	47.2	Taylor et al. (1985)
Citlerichthys stigmaeus	96-hour LC50	30	Mearns et al. (1976)
Cyprinodon variegates	96-hour LC50	25 21.4b	Jop et al. (1987) Dorn et al. (1987)
Gasterosteus aculcatus*	96-hour LC50	33 35b	Jop et al. (1987)
Limanda limanda	96-hour LC50	47	Taylor et al. (1985)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on a review of existing fish data from the EU RAR, an acceptable assessment of acute toxicity was achieved.

Executive summary:

Based on a review of existing fish data from the EU RAR, an acceptable assessment of acute toxicity was achieved.

The acute toxicity of chromium (VI) to fish appears to be dependent on the water hardness and also pH. Higher toxicity has generally been seen in soft water and at more acidic pHs, particularly those <6.5. This dependence appears to follow a similar pattern to the uptake of chromium (VI) by fish (see Section 3.1.1.2.4), where it has been postulated that at lower pHs, the main form of chromium (VI) in solution is the monovalent HCrO4 - ion, which has been postulated as having a higher mobility across cell membranes than the divalent chromium (VI) oxyanions found at higher pH.

For some fish species, toxicity data are available for more than one of the chromium (VI) compounds included in this assessment. The available information indicates that, when expressed on a total chromium concentration, there are no significant differences between the toxicity of sodium chromate, sodium dichromate and potassium dichromate (allowing for differences in water properties). This is as would be expected if the equilibria between the chromate and dichromate anions are established in the test medium. Little information is available for ammonium dichromate and chromic acid, but it would be expected that their toxicity would be similar to that of the other chromates/dichromates, when expressed on a total chromium concentration basis.