4-(4-methoxyphenyl)butan-2-one

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

Study period:

2016-05-18 to 2016-05-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

at start and end of experiment

Details on sampling:

- Sampling method: at start and at end of experiment
- Dilution: using mobile phase, 40% acetonitrile, 60% HPLC water
- Sample storage conditions before analysis: 6 +/- 2 °C

Vehicle:

no

Details on test solutions:

- Stock solution: 100 mg/L mixed by manual agitation; freshly prepared with dilution water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: straus, clone 5
- Source: available in study report
- Age at start of experiment: Less than 24 h old. No first brood progency used.
- Feeding during test: No feeding during the test
- Feeding of culture (before test): 5 times per week, ad libitum with mix of unicellular algae
- Culture medium: Elendt M4
- Application: 20 mL test solution per test vessel, daphnids inserted with small amount of dilution water by a pipette.

ACCLIMATION
- Acclimation period: no acclimatisation as dilution water was equivalent to culture medium

Test type:

static

Water media type:

other: Elendt M4

Limit test:

no

Total exposure duration:

48 h

Hardness:

167 mg CaCO3/L

Test temperature:

20.3°C, constant within +/- 1°C

pH:

at start: approx. pH 8.9, at end of experiment: approx. pH 7.7

Dissolved oxygen:

at start: approx. 8.9 mg O2/L, at end of experiment: approx. 8.6 mg O2/L

Conductivity:

476 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 6.25, 12.5, 25, 50 and 100 mg/L
Measured concentrations (0 h): 6.36, 12.3, 25.0, 49.8 and 102 mg/L
Measured concentrations (48 h): 6.38, 12.4, 25.0, 49.5 and 101 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker, 50 mL capacity
- Type: loosely covered with watch glass
- Material, size, headspace, fill volume: 50 mL, filled with 20 mL test solution, 4x7 cm, glass
- No. of organisms per vessel: 5 daphnids
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium, same as culture medium.

OTHER TEST CONDITIONS
- Adjustment of pH: 8.2 +/- 0.8
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: Diffuse light, max. 20 µE/m2/s

EFFECT PARAMETERS MEASURED: Immobilisation

RANGE-FINDING STUDY
- Test concentrations: 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: Only at 100 mg/L effect on immobilisation observed (mean of 30 % immobilisation)

Reference substance (positive control):

yes

Remarks:

Potassium dichromate tested once per month

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Nominal concentrations verified by measurements

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Nominal concentrations verified by measurements

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Nominal concentrations verified by measurements

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Nominal concentrations verified by measurements

Details on results:

- Observations in control group: no immobilisation, no signs of disease or stress.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 = 2.08 mg/L, which is within the required range of 0.6 to 2.4 mg/L
- Dose-response test: yes

Reported statistics and error estimates:

An ECso-value was calculated only for the reference item by sigmoidal dose-response regression. The respective 95% confidence limits for the ECs was calculated from the standard error and the t-distribution. All calculations were carried out from the best-fit values with the software GraphPad Prism5.

Immobilisation was only observed at 100 mg/L test item. Immobilisation ranged between 20 and 40 % with mean value of 30 %

nominal test concentration (mg/L)	Immobilisation (%)
	24 h					48 h
	Rep 1	Rep 2	Rep 3	Rep 4	Mean	Rep 1	Rep 2	Rep 3	Rep 4	Mean
100	0	0	0	0	0	40	20	40	20	30
50	0	0	0	0	0	0	0	0	0	0
25	0	0	0	0	0	0	0	0	0	0
12.5	0	0	0	0	0	0	0	0	0	0
6.25	0	0	0	0	0	0	0	0	0	0
control	0	0	0	0	0	0	0	0	0	0

Measured exposure concentrations during the Definitive Test:

Sampling date	2016-05-18 Start of the exposure (0 hours)		2016-05-20 End of the exposure (48 hours)
Start of analysis	2016-05-18		2016-05-20
Nominal conc. (mg/L)	Measured conc. (mg/L)	%	Measured conc. (mg/L)	%
100	102	102	101	101
50.0	49.8	100	49.5	99
25.0	25.0	100	25.0	100
12.5	12.3	98	12.4	99
6.25	6.36	102	6.38	102
Control	< LOQ		< LOQ

 

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were verified and fulfilled.

Conclusions:

The 48-hour EC50 for Daphnia magna is above 100 mg/L and the NOEC is 50 mg/L.

Executive summary:

The short-term toxicity to Daphnia magna was determined according to OECD 202 guideline. The study was conducted under static conditions. The daphnids were exposed over a period of 48 hours to 5 concentrations of the test item (0, 6.25, 12.5, 25, 50 and 100 mg/L). The test substance concentrations remained constant during the test period as measured concentrations were in the range of 98 to 102 % of the nominal values. The validity criteria were fulfilled. The EC50 value was determined to be > 100 mg/L and the NOEC is 50 mg/L.

Description of key information

OECD 202 (Daphnia magna): EC50 > 100 mg/L (nominal concentrations)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L