Butanone oxime

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD and GLP guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

(draft guideline, April 1997)

GLP compliance:

yes

Analytical monitoring:

yes

Details on test solutions:

Nominal concentrations of 100, 50.0 or 25.0 mg MEKO/L and a laboratory water control. Solubilizer was not used. Concentrations of the test substance were close to the nominal concentrations throughout the 21-day test(95.3 to 105%).

Test organisms (species):

Daphnia magna

Details on test organisms:

10 daphnids (10 replicates; 1 daphnid per replicate)

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Hardness:

36.6 to 41.4
mgCaC03/L.

Test temperature:

20.2 - 20.6C

pH:

7.4 - 7.8

Dissolved oxygen:

8.1 - 8.8 mg/l

Nominal and measured concentrations:

25, 50, and 100 mg/l nominal with corresponding measured levels 100 to 105% at preparation and from 95.3
to 99.9% after 2-3days from preparation

Details on test conditions:

TEST SYSTEM
- Test vessel:16-hour light (below 1,200 lux)/8-hour dark
- Material, size, headspace, fill volume: 80 ml
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates):10
- No. of vessels per control (replicates):10

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod/ Light intensity:16-hour light (below 1,200 lux)/8-hour dark

RANGE-FINDING STUDY : Results of acute daphnia immoblization used, the EC50 was 201 mg/l

Reference substance (positive control):

not required

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

rate

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

rate

Details on results:

- Mortality of parent animals: 30% in controls, 20% at 25 mg/l, no mortality at 50 or 100 mg/l
- Size and conditions of parental daphinids of each test level were almost similar to control

Validity criteria fulfilled:

not specified

Conclusions:

For the freshwater crustacean Daphnia magna, the 21-day NOEC and EC50 (reproduction rate) are both >100 mg MEKO/L.

Description of key information

The 21-d NOEC of =100 mg/L for Daphnia magna will be used in the assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

One long-term toxicity test with Daphnia magna is available for MEKO (Kurume Laboratory, 1998d). The study is a semi-static test performed under GLP according to OECD Guideline 211 with analytical monitoring. The 21-d NOEC for reproduction is =100 mg/L.