N-pentan-2-ylidenehydroxylamine

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

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

Details on sampling:

The concentrations of methyl propyl ketoxime in the test solution were measured at 0 and 96 hours using a high performance liquid chromatography method.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Test material weighed, added to water in beaker, stirred vigourously for 10 minutes. (concentration 100 mg/l)

Final solutions were clear and colorless.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name:rainbow trout
- Strain: O. mykiss
- Source: Houghton Springs Fish Farm, Winterbourne Houghton, Blandford Forum, Dorset DT11, 0PD
- Length at study initiation : 44 - 52 mm, mean 49 mm
- Weight at study initiation : range 1.10 – 1.96 g, mean 1.55 g
- Feeding during test: none


ACCLIMATION
- Acclimation period: at least 7 days
- Acclimation conditions: same as test
- Type and amount of food: proprietary brand of high protein pelleted fish food
- Feeding frequency:daily
- Health during acclimation : no mortality observed

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

na

Hardness:

46.3 mg/l CaCO3

Test temperature:

14.5 - 15.2 °C

pH:

7.2 - 7.57

Dissolved oxygen:

73 - 92%

Salinity:

NA

Nominal and measured concentrations:

nominal 100 mg/l, measured 102 mg/l at 0 hour and 103 mg/l at 96 hours

Details on test conditions:

TEST SYSTEM
- Test vessel: glass tanks (external dimensions L×W×H;610×305×310)
- Material, size, headspace, fill volume: working volume of 30 litres
- Aeration: gentle aeration
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:tap water coarsely filtered to remove particulate material, passed through activated carbon and dechlorinated using sodium thiosulphate. Salts ifrequired to maintain minimum hardness levels. Treated water passed through ultraviolet steriliser and filtered to 10 µm
- Total organic carbon: 2.35 mg/l dissolved organic carbon
- Particulate matter: < 3 mg/l as suspended solids
- Metals: not reported
- Pesticides: < 0.01 ug/l
- Chlorine: < 2 u/l as Cl2 (free and total)
- Alkalinity:26.4 m/l CaCO3
- Ca/mg ratio: not reported
- Conductivity: 213 us/cm
- Culture medium different from test medium:
- Intervals of water quality measurement: daily to quarterly depending on parameter


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mortality and symptoms of toxcitiy after 3, 24, 48, 72 and 96 hours

OTHER TEST CONDITIONS
- Adjustment of pH:Not needed
- Photoperiod: 16 h light, 8 h darkness


TEST CONCENTRATIONS
- Spacing factor for test concentrations: NA limit test
- Range finding study: yes
- Test concentrations: 10 and 100 mg/l
- Results used to determine the conditions for the definitive study: 1 dead at 10 mg/l, none at 100 mg/l.

Reference substance (positive control):

not required

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

ca. 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality and signs of toxicity

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: none observed
- Observations on body length and weight: none observed
- Other biological observations: none observed
- Mortality of control: none observed
- Other adverse effects control: none observed
- Abnormal responses: none observed
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none observed
- Effect concentrations exceeding solubility of substance in test medium: none observed

Results with reference substance (positive control):

NA

Reported statistics and error estimates:

NA

Sublethal observations / clinical signs:

Table 1: Validity criteria for OECD 203.

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	0%	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	68 to 92%	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20%, results should be based on the measured concentration.	102-103% of nominal	yes

 

Validity criteria fulfilled:

yes

Remarks:

Please refer to Table 1 at "Any other information on results incl. tables"

Conclusions:

No mortality or signs of toxicity were observed in raindbow trout exposed to 100 mg/l (nominal; 102 mg/l measured) test substance for 96 hours.

Description of key information

LC50 (96 h) > 100 mg/L (nominal, OECD 203).

Additional information

The acute toxicity of 2-Pentanone oxime to fish was tested in a GLP guideline study following OECD 203. The study was conducted as a static limit test at a nominal test substance concentration of 100 mg/L. The substance concentration was analytically verified by HPLC. The measured test substance concentrations were 102 mg/L at test start and 103 mg/L at test end after 96 hours. Ten fish of the species Oncorhynchus mykiss were used as test organisms. Mortality or symptoms of toxicity were not observed. The reported LC50 (96 h) is > 100 mg/L (nominal).