Chromium tris(dihydrogen phosphate)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 days

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited details of methodology used available.

Justification for type of information:

As with all inorganic salts, the significance for toxicity or environmental assessment is the presence of specific ions that will form when in solution or when in biological systems.In the case of Cr III salts, the counter ion will have an effect on solubility and this is itself dependant on the type of media being used and in particular the pH of that media. It is generally accepted that in the case of metal salts, testing with salts that are soluble in the respective test media will ensure maximum exposure of the metal ions. This will include chlorides and nitrates as being more soluble and will indeed have relevance when dissolved in acid media, such as if ingested.Read-across to other chromium III salts is therefore considered valid as long as the exposure in the test system is greater than would be expected for the substance under review for registration. No further testing is justified.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

Basic principles for LC50 followed.

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

No sample methods cited

Vehicle:

no

Details on test solutions:

Solutions of 0, 100, 200, 400, 800 mg/l as Chromium III sulphateEquivalent to 0, 31.5, 63, 126, 252 mg/l as Cr

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM- Common name: Cyprinus carpio (Common carp)- Length at study initiation (length definition, mean, range and SD): 4 cm - 6cmTEST ORGANISM- Common name: Aristichthys nobilis (Big head)- Length at study initiation (length definition, mean, range and SD): 4 cm - 6cm

Test type:

static

Water media type:

freshwater

Total exposure duration:

10 d

Remarks on exposure duration:

Extended for 10 days with an abjective of performing pathology on the fish. 96 hour mortalities noted and 96 hour EC50 included in the report

Hardness:

195 mg/g as Ca CO3

Test temperature:

Not specified

pH:

Not specified

Dissolved oxygen:

Not specifiedAir bubbled through the tanks for duration of exposure.

Nominal and measured concentrations:

Nominal:0, 100, 200, 400, 800 mg/l as Chromium III sulphate
Equivalent to 0, 31.5, 63, 126, 252 mg/l as Cr

Details on test conditions:

TEST SYSTEM- Test vessel: Plastic containers measuring 20 x 40 x 60 cm holding 4 l of water- Aeration: Compressed air supplied to each tank throughout the test via submerged 1.5 cm3 diffusers- No. of organisms per vessel: 18 -20- No. of vessels per concentration (replicates): 2TEST MEDIUM / WATER PARAMETERS- Source/preparation of dilution water: tapwaterTEST CONCENTRATIONS- Test concentrations: 100, 200, 400 800 mg/l

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

97.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Cyprinus carpio

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

151.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Aristichthys nobilis

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

371.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Cyprinus carpio

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

363 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mortality (fish)

Remarks on result:

other: Aristichthys nobilis

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 30 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Cr 3+

Basis for effect:

mortality (fish)

Remarks on result:

other: C carpio

Details on results:

C. Carpio treated with 200 mg/l chromic sulphate had small particles in the gills of treated fish and a loss of epithelial cells. Lesions of the liver were observed with hypertrophy and congestion of the hepatic cells and small particles were noted in some cells. Imn the intestine, there was disintegration of epithelial cells and small particulates were observed in the microvilli region.

Validity criteria fulfilled:

yes

Conclusions:

Considered scientifically valid although not meeting certain quality criteria.
LC50 estimated in terms of Cr 3+ for C carpio is 30 mg/l
LC50 estimated for chromium hydrogen phosphate is 113 mg/l

Executive summary:

The effects of chromic sulphate on the common carp, Cyprinus carpio and the bighead, Aristichthys nobilis, were studied. C. carpio was found to be more susceptible than A. nobilis to chromic sulphate at the lowest concentration tested (100 mg/l) whereas results obtained at other concentration were similar for both species. Damage to the gills, liver and intestine was observed by histopathological examination

LC50 estimated in terms of Cr 3+ for C carpio is 30 mg/l

LC50 estimated for Chromium hydrogen phosphate = 113 mg/l

Description of key information

LC50 estimated in terms of Cr 3+ for C carpio is 30 mg/l

LC50 estimated for Chromium hydrogen phosphate = 113 mg/l using nominal molecular weight

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

113 mg/L