Dipotassium tetraoxomolybdate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

dec 1991-march 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: tests were performed according to international guidelines but there are no measured data available

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EEC directive 67/548 annex V C1 as published in 84/449/EEC

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Diammonium dimolybdate

EC Number:

248-517-2

EC Name:

Diammonium dimolybdate

Cas Number:

27546-07-2

IUPAC Name:

Diammonium dimolybdate

Details on test material:

- form: white powder
- purity: 39,7 % molybdenum
- date of receipt: 7/10/1991
- expiry: 7/10/1993
- storage: in darkness at room temperature
- method of preparation: direct dispersion in water
- stability of test concentration: ensured by daily renewal of test media

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

- acclimatisation: stock held since 20/11/1991 and acclimatised to test conditions from 20/11 to 17/12/1991
- temperature: 14 degrees Celsius
- feeding: daily, with commercial trout pellet. discontinued 24h prior to test
- mortalities: 0% in 7 days prior to study
- medication: none
- mean standard length: 4,6 cm (SD 0,3 cm)
- mean weight: 1,72 g (SD 0,36 g)

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

150-200 mg/L

Test temperature:

14 degrees Celsius

pH:

5.7

Dissolved oxygen:

>= 10.1 mg O2/L

Nominal and measured concentrations:

5 test concentrations + 1 control:
100, 180, 320, 560, 1000 mg/L

Details on test conditions:

- test water: lab tap water, dechlorinated and softenend


EXPOSURE CONDITIONS
- test vessel: glass aquaria holding 20 L of test media
- experimental design: 10 animals per test concentration
- method of initiation: fish were placed in prepared test media
- loading: 0,86 g bodyweight/litre
- photoperiod: 16h light:8h dark
- temperature: 14 degrees Celsius
- aeration: via narrow bore glass tubes
- medium renewal: daily
- criteria of death: absence of respiratory movement and response to physical stimulation

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

420 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 320-560

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The tests were performed according to international guidelines but there are no measured data available. The study is well performed and documented.