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

Study period:

10 Mar - 22 Jul 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

temperature marginally outside of range on two days (considered to have no effect)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Analytical monitoring of the test substance in the test medium was carried out during five test Intervals in all treatments. Sampling was performed at the start and the end of the Interval. Four 48 hour and one 72 hour intervals were surveyed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: For the preparation of stock solution (100 mg/L) one 2 L beaker was filled with 1 L of medium, stirred by magnetic stirrer (300 rpm) and 100 mg test substance was added. The preparation was stirred for 24 h and was then filtered through a filter paper circle (Ø 320 mm, Whatman Schleicher & Schuell, Dassel, Germany).

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:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

2.2 – 3.2 (mmol/L)

Test temperature:

20.0- 23.0 °C

pH:

7.5 – 8.5

Dissolved oxygen:

5.0 - 6.3 mg/L

Nominal and measured concentrations:

Nominal: 0.18, 0.45, 1.12, 2.8 and 7.0 mg/L
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: 150 mL glass beakers with 70 mL test solution
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): 3 times per week
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: demineralized water
- Total organic carbon: < 2 mg/L
- Alkalinity: 0.5 - 1.5 mmol/L
- Conductivity: 500 - 700 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: Temperature, oxygen saturation and pH value were measured after each renewal interval on Mondays, Wednesdays and Fridays in the test concentrations and the control, each in old and new media. Temperature and pH value were measured concurrently by a pH meter (Microprocessor pH340, Sentix Mic, WTW). Light intensity was measured once a week by Lux meter. Once a week total hardness of new and old media was determined in the controls and the highest test concentration.

OTHER TEST CONDITIONS
- Adjustment of pH: self-adjusting
- Photoperiod: 16 hours light/ 8h dark
- Light intensity: 1000 -1300 Lux

EFFECT PARAMETERS MEASURED: At the end of the test survival/Immobility of the parent animals and the total number of living offspring produced per parent animal alive was assessed, Juveniles. produced by adults that died during the test, were excluded from calculations.

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

2.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

loading rate WAF

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

loading rate WAF

Basis for effect:

mortality

Details on results:

The results of this study show that the test substance induced no statistically significant mortality/immobility to parent animals. Effects on reproduction rate of Daphnia magna were observed at nominal 7.0 mg/L.

Regarding analytically detennined concentrations, no usable values could be detected (< 0.01 mg/L). Therefore, EC values given in this report are based on the nominal concentration (see OECD series on testing and assessment, no. 23: Guidance document on aquatic toxicity testing of difficult substances and mixtures- (ENVIJM/MON0(2000)6), Chapter 5, page 43).

Validity criteria fulfilled:

yes

Conclusions:

In a study according to the OECD guideline 211 (21-day Daphnia reproduction test) under GLP, the 21d-NOELR value for the test substance is determined to be 2.8 mg/L based on the nominal concentration.

Executive summary:

The long-term toxicity of the test substance to Daphnia magna was investigated in a study according to OECD guideline 211 under GLP conditions. Daphnia were exposed to the test substance, prepared by 24h stirring and subsequent filtering, for 21 days in a semi-static test. As the analytical measurements were not reproducible (probably due to the low water solubilioty and hydrolysis), nominal concentrations were reported. All validity criteria (no immobilised Daphnia in control group with a mean offspring of 104 (> 60) and a variation of CV=7.3%) were met. No significant mortality was observed, while effects on reproduction rate of Daphnia magna were observed at nominal 7.0 mg/L. Thus, the lowest 21d-NOELR value was obtained for reproduction and is determined to be 2.8 mg/L loading rate WAF.

Description of key information

NOELr (21d) = 2.8 mg/L (nominal, WAF) for reproduction of Daphnia magna (OECD 211)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.8 mg/L

Additional information

One study investigating the long-term toxicity of the test substance to aquatic invertebrates is available. The study was performed according to GLP and OECD guideline 211 using Daphnia magna as test organism (Wehrhahn 2010). Test solutions ranging from 0.18 to 7.0 mg/L were prepared by direct adding test substance to the test medium, 24h stirring and subsequent filtering. The test organisms were exposed for 21 days under semi-static conditions. As the analytical measurements were not reproducible (probably due to low water solubility and hydrolysis), nominal concentrations were reported. All validity criteria (no immobilised Daphnia in control group with a mean offspring of 104 (> 60) and a variation of CV=7.3%) were met. No significant immobility was observed, while effects on reproduction rate of Daphnia magna were observed at nominal 7.0 mg/L. Thus, the lowest 21d-NOELR value was obtained for reproduction and is determined to be 2.8 mg/L loading rate WAF.