1-(2-hydroxy-5-nonyl(branched)-phenyl)ethanone oxime

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-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: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations, method: Six samples in 40 mL beakers were prepared for analytical determinations. 200 mL test solution from the concentration Ievels 2.5; 5, 10, 20 and 40 mg/L and pure M4 medium (control, only 0h) were filled each into the beakers end stored under the same conditions as the test vessels. After 0, 24 and 48 h, 30 mL of each sample was transformed to a 50 mL glass flask, which was closed with screw cap and were immediately shipped to Ihe test site. Analytical determinations were performed on the same day.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: For the preparation of stock concentration (100 mg/L) one 2 L beaker was filled wih 1 L of M4 medium, stirred by magnetic stirrer (300 rpm) and 100 mg test substance were added. The preparation was stirred for 24 h and was filtered through a filter paper circle (320 mm). The amounts corresponding to the test concentrations were pipetted into a gratuated flask, made up to a total volume of 500 mL with M4 medium, and then transferred to the test vessels.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): After filtration all test cocentrations were present as clear solutionts.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture originally obtained from Landesumweltamt (NRW)”, Düsseldorf, Germany (on 30 May 2006)
- Feeding during test: yes
- Food type: algae (Desmodesmus subspicatus)
- Amount: based on the amount of organic carbon provided to each parent animal (0.1-0.2 mg carbon)
- Frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.556 mmol/L

Test temperature:

20.0 - 21.0 °C

pH:

7.92 - 8.16

Dissolved oxygen:

5.7 - 6.5 mg/L

Nominal and measured concentrations:

Nominal: 2.5, 5, 10, 20 and 40 mg/L loading rate WAF
Measured: Analytical results show that recovery of test substance was very low using LC-MS analysis (< 0.01 mg/L). Thus, effects were attributed to the nominal concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers with 30 mL test solution
- Aeration: The vessels were not aerated because of risk of floating daphnia to the water surface.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 5

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: demineralized water
- Total organic carbon: 1.4 mg/L
- Alkalinity: 1.23 mmol/L
- Conductivity: 564 µS/cm
- Intervals of water quality measurement: Temperature, oxygen saturation and pH value were measured daily in an additional beaker.

OTHER TEST CONDITIONS
- Photoperiod: 16h light/ 8h dark
- Light intensity: 700 +/- 50 lux

EFFECT PARAMETERS MEASURED: Immobilisation was recorded after 24 and 48h test duration.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

9.55 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Mortality of control: No mortality was observed.
- Other adverse effects control: no
- Abnormal responses: no

Table 1: Analytical results of LC-MS analysis

Nominal concentration [mg/L]	Measured concentration
	0h	24h	48h
control	< 0.01	-	-
2.5	0.012	0.013	< 0.01
5	0.020	0.019	< 0.01
10	0.081	0.049	0.012
20	0.160	0.104	0.042
40	0.511	0.042	0.124

Validity criteria fulfilled:

yes

Conclusions:

In a GLP study according to OECD guideline 202, the 48h-EL50 value for acute toxicity of the test substance to Daphnia magna was determined to be 9.55 mg/L.

Executive summary:

The study was performed according to OECD guideline 202 under GLP conditions. In a static study Daphnia magna was exposed to the test substance for 48 h. Loading rate WAFs between 2.5 and 40 mg/L were tested. Analytical monitoring was performed but showed that recovery of test substance was very low using LC-MS analysis. Thus, effects were attributed to the nominal concentration. All validity criteria were fulfilled. The 48h-EL50 value is determined to be 9.55 mg/L based on nominal concentrations.

Description of key information

EL50 (48h) = 9.55 mg/L (nominal, WAF) for Daphnia magna (OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

9.55 mg/L

Additional information

One study investigating the short-term toxicity of the test substance to aquatic invertebrates is available. The study was performed according to GLP and OECD guideline 202 using Daphnia magna as test organism (Wehrhahn 2010). Loading rate WAFs between 2.5 and 40 mg/L were tested. Analytical monitoring was performed but showed that recovery of test substance was very low using LC-MS analysis. Thus, effects were attributed to the nominal concentration. All validity criteria were fulfilled. The 48h-EL50 value is determined to be 9.55 mg/L based on nominal concentrations.