3-(dimethylamino)propylurea

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:

2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

The test was carried out using juvenile rainbow trout (Oncorhynchusmykiss). Fish were obtained from Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK and maintained in-house since 26 August 2004. Fish were maintained in a glass fibre tank with a "single pass" water renewal system. Fish were acclimatised to test conditions from 22 September 2004 to 4 October 2004. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.

Test type:

semi-static

Limit test:

yes

Details on test conditions:

Fish were maintained in a glass fibre tank with a "single pass" water renewal system. Fish were acclimatised to test conditions from 22 September 2004 to 4 October 2004. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.
The water temperature was controlled at approximately 14°C with a dissolved oxygen content of greater than or equal to 9.7 mg O2/l. These parameters were recorded daily. The stock fish were fed commercial trout pellets which was discontinued approximately 24 hours prior to the start of the definitive test. There was zero mortality in the 7 days prior to the start of the test and the fish had a mean standard length of 4.5 cm (sd = 0.3) and a mean weight of 1.10 g (sd = 0.21) at the end of the definitive test. Based on the mean weight value this gave a loading rate of 0.39 g bodyweight/litre.
The diet and diluent water are considered not to contain any contaminant that would affect the integrity and outcome of the study.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Validity criteria fulfilled:

yes

Conclusions:

The 96-Hour LC50 based on nominal test concentrations was greater than 100 mg/l and correspondingly the No Observed Effect Concentration was 100 mg/l.

Executive summary:

Following a preliminary range-finding test fish were exposed, in two groups of seven, to an aqueous solution of the test material, at a single concentration of 100 mg/l for a period of 96-hours at a temperature

of approximately 14 degrees C under semi-static test conditions. The number ofmortalities and any sublethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of

exposure and then daily throughout the test until termination after 96 hours.

The 96-hour LC50 based on nominal test concentrations was greater than 100 mg/l and correspondingly the No Observed Effect Concentration was 100 mg/l.

It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/l.

Analysis of the test preparations at 0, 24 and 96 hours showed measured test concentrations to range from 95 % to 101 % of nominal and so the results are based on nominal test concentrations only.

Description of key information

The 96-Hour LC50 based on nominal test concentrations was greater than 100 mg/l and correspondingly the No Observed Effect Concentration was 100 mg/l.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

100 mg/L