Butanone oxime

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The test parameters evaluated in this study comply with a specific test guideline (Dutch NEN 6504), are well documented, scientifically acceptable, but not performed according to GLPs. Study was described in OECD HPV documents but original study could not be located for REACH

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: Dutch NEN 6504

GLP compliance:

no

Analytical monitoring:

no

Details on test solutions:

Concentrations used were 0, 180, 320, 560, 1000 and 1800 mg/L. Solutions were refreshed after 48 hours.

Test organisms (species):

Poecilia reticulata

Details on test organisms:

10 fish/concentration were used. The test was performed in duplicate.

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

96 h

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

ca. 180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

behaviour

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

ca. 560 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

- no lethality was observed.

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 760 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Conclusions:

For the freshwater fish Poecilia reticulata, the calculated 96-hour LC50 is 760 mg MEKO/L. The 96-hour LC0 is 560 mg MEKO/L and the no-observed-effect concentration (behaviour) is 180 mg MEKO/L .

Reference 2

Endpoint:

short-term toxicity to fish

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 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all
- Sampling method:Equal volume of the test solution was taken out from the middle layer of the two test vessels in each test level and the mixture was used for the measurement by HPLC analysis

Vehicle:

no

Details on test solutions:

10 Orzias latipes (2 replicates; 5 organisms per replicate) were exposed to the nominal concentration of 100 mg/L and laboratory water control (dechlorinated water). Solubilizer was not used. Concentrations of the test substance were close to the nominal concentrations (102 to 104%).

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name:Medaka
- Strain:Oryzias latipes
- Source:Nakashima Fish Farm
- Length at study initiation:1.9 em (1.8 to 2.1 em)
- Weight at study initiation :0.11 g (0.077 to 0.14 g)
- Feeding -no

ACCLIMATION
- Acclimation period: 12 days or less
- Acclimation conditions:same as test
- Type and amount of food:TetraMin
- Health during acclimation (any mortality observed): < 5%

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

96 h

Hardness:

40.5 mgIL (as CaC03)

Test temperature:

24±1°C

pH:

7.1 to 7.6

Dissolved oxygen:

dissolved oxygen concentration ranged from 6.9 to 8.3

Salinity:

not applicable

Nominal and measured concentrations:

The ratio of the measured concentration to the nominal value ranged 104% at the start of the exposure, 102% before the renewal

Details on test conditions:

TEST SYSTEM
- Test vessel:3.0 L Glass tank (diameter 16 cm, depth 17 cm)
- fill volume: 2.5 l/vessel
- Renewal rate of test solution ):at 48 hours of exposure
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates):2
- No. of vessels per control (replicates):2

OTHER TEST CONDITIONS
- Photoperiod/light intensity:16-hour light/8-hour dark photoperiod daily with room lamp


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline:
- Range finding study: no mortality at 100 mg/l
- Test concentrations: 100 mg/l

Reference substance (positive control):

yes

Remarks:

CUS04 5H20

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

- no fish died at 100 mg/L

Details on results:

- Behavioural abnormalities: none
- Mortality of control: none

Results with reference substance (positive control):

The acute toxicity test of the reference substance
[CUS04 5H20 (Reagent chemical), Wako Pure Chemical Industries, Ltd.] was
conducted. The 96-hours LC50 was 0.930 mglL
- Results with reference substance valid? yes
- LC50:0.930 mglL

Validity criteria fulfilled:

yes

Conclusions:

For the freshwater fish Oryzias latipes, the NOEC is estimated to be greater than 100 mg MEKO/L.

Description of key information

The 96-h LC50 of >100 mg/L in Oryzias latipes will be used in the assessment.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

Two short-term toxicity studies with freshwater fish are available for MEKO. In the first one, a semi-static GLP-compliant test with Oryzias latipes, performed according to OECD Guideline 203 with analytical monitoring, the 96-h LC50 value is >100 mg/L (Kurume Laboratory, 1998a). As the measured concentration was within 80% of the nominal concentrations, the nominal concentration was used. In the second study, a semi-static test with Poecilia reticulata, performed according to Dutch NEN 6504, a 96-h LC50 of 760 mg/L has been reported (OECD, 1998). Even though the study withOryzias latipes gives no absolute result, as a worst-case assumption, this study is regarded as the key study as no analytical monitoring is performed in the test with Poecilia reticulata.