Propanoic acid, 2-(4-chloro-2-methylphenoxy)-, 2-ethylhexyl ester, (2R)-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to section 13 for "Read Across justification".

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Part I

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Purity: 89.7 %
Batch: DA 928

Analytical monitoring:

yes

Details on sampling:

Test concentrations were verified by chemical analysis. Water samples (200 mL in duplicate) were taken from the control and each exposure level (replicates pooled) at 0 hours and 48 hours.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Straus
- Source: Laboratory culture originating from a strain supplied hy the Institute National de Recherche Chimique Appliquee (IRChA), France
- Culture: Brood stocks of Daphnia magna were cultured under a 16 h light : 8 h dark photoperiod at 23 ± 2 °C in polypropylene vessels containing 2 litres of Elendt M7 medium. Cultures were fed daily with a suspension of mixed algae (predominantly Scenedesmus and Selenastrum spp.). Culture conditions ensure that reproduction is by parthenogenesis.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

no data

Test temperature:

22 °C

pH:

7.0 - 7.8

Dissolved oxygen:

8.2 - 8.4 mg/L

Salinity:

NA

Conductivity:

no data

Nominal and measured concentrations:

Nominal concentrations: 0, 1, 2.2, 4.6, 10, 22, 46 and 100 mg/L (Calculated test concentrations: 0.83, 2.0, 3.9, 9.0, 20, 42 and 91 mg/1. Adjusted for purity (Measured concentration of MCPP-P x 100 / 89.7))
The measured concentrations ranged from 81 - 92 %.

Details on test conditions:

- Test medium: Elendt M7 medium was prepared using analytical grade reagents and reverse osmosis purified water.
- Test substance preparation: The test substance was dispersed in test water and stirred for 2 hours to give an initial stock solution of 100 mg/L. This solution was passed through a sieve (of approximately 0.5 mm2 mesh size) to remove particulate matter before serial dilutions were prepared with test water to give the desired series of exposure levels.
- Experimental design: Seven test concentrations plus one control each in duplicate (20 animals per test group). Ten 1st instar Daphnia were placed at random in each glass jar containing 200 mL of prepared test medium or diluent water only, as appropriate, to give a loading of 20 mL test solution per organism. The jars were loosely covered with aluminium foil to minimise evaporation losses.
- Environmental conditions: Cultures were maintained at 22 °C under a photoperiod of 16 hours light : 8 hours dark and without supplementary aeration or feeding during the 48 hour exposure period.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Verification of test concentration

The analytical method was proven satisfactory with regard to linearity, accuracy and precision with a mean validation recovery of 104 %: coefficient of variation 6.2 %.

A static test system was used from which one set of test solutions, consisting of fresh and expired samples was analysed during the two clays of the study. The mean measured test concentration was 89.5 % of nominal (fresh media) and 87.9 % of nominal (expired media).

Validity criteria fulfilled:

not specified

Remarks:

expected to be a valid source

Conclusions:

For MCPP-P acid, the hydrolysis product of MCPP-P 2-EHE, a 48h-EC50 > 91mg/L and a 48h-NOEC of 91 mg/L were determined on Daphnia magna.

Executive summary:

MCPP-P 2-EHE hydrolyses rapidly in natural water. Therefore, the hydrolysis product MCPP-P acid was used for further assessment of MCPP-P 2-EHE with respect to toxicity to Daphnia magna.

 

A study was performed to assess the acute toxicity of MCPP-P to Daphnia magna. The study was conducted in accordance with EEC Methods for Determination of Ecotoxicity Annex to Directive 92/69/EEC (0.J No. L383A, 29.12.92) Part C, Method 2 "Acute toxicty for Daphnia" and OECD Guideline for Testing of Chemicals No. 202, Part 1 "Daphnia, Acute Immobilisation Test". Groups of 20, 1st instar Daphnia (less than 24 hours old) were exposed for 48 hours to 7 concentrations of MCPP-P dispersed in Elendt M7 medium. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours and the following values were determined:

24h-EC50 > 91 mg/L

48h-EC50 > 91 mg/L

Lowest test concentration resulting in 100% immobilisation: > 91 mg/L, "no-observed effect level" (NOEC) at 48 h: 91 mg/L

All results based upon measured concentrations expressed as the calculated equivalent concentration of MCPP-P (as supplied). Measured concentrations ranged from 85 - 92 % of nominal at 0 hours and 81 - 90 % of nominal at 48 hours.

Description of key information

In a key study, the 48 hour-EC50 for Daphnia magna of MCPP-P acid was determined to be > 91 mg/L and the NOEC was determined to be 91 mg/L.

Additional information

MCPP-P 2-EHE hydrolyses rapidly in natural water. Therefore, the hydrolysis product MCPP-P acid was used for further assessment of MCPP-P 2-EHE with respect to toxicity to Daphnia magna.

 

A study was performed to assess the acute toxicity of MCPP-P to Daphnia magna. The study was conducted in accordance with EEC Methods for Determination of Ecotoxicity Annex to Directive 92/69/EEC (0.J No. L383A, 29.12.92) Part C, Method 2 "Acute toxicty for Daphnia" and OECD Guideline for Testing of Chemicals No. 202, Part 1 "Daphnia, Acute Immobilisation Test". Groups of 20, 1st instar Daphnia (less than 24 hours old) were exposed for 48 hours to 7 concentrations of MCPP-P dispersed in Elendt M7 medium. The incidence of immobilisation was recorded for each test and control group at 24 hours and at 48 hours and the following values were determined:

24h-EC50 > 91 mg/L

48h-EC50 > 91 mg/L

Lowest test concentration resulting in 100% immobilisation: > 91 mg/L, "no-observed effect level" (NOEC) at 48 h: 91 mg/L

All results based upon measured concentrations expressed as the calculated equivalent concentration of MCPP-P (as supplied). Measured concentrations ranged from 85 - 92 % of nominal at 0 hours and 81 - 90 % of nominal at 48 hours.