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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
18 April - 12 May 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
13 April 2004
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Version / remarks:
30 May 2008
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
chemical analyses were performed non-GLP

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
impurity
Type:
impurity
Test material form:
liquid: volatile
Details on test material:
Batch No: 57161235
Storage: Room temperature (approx. 20°C)

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
The following test vessels were set up:
- Test solution (Tn); containing Daphnia medium with test item (two replicates with 20 Daphnia each)
- Blank control (Bn); containing pure Daphnia medium (three replicates with 20 Daphnia each)
- Since the test item is volatile, the test solutions were prepared, separately for each test concentration, by direct addition (pipetting) of the respective quantities of test item to Daphnia medium, considering a density of about 0.904 g/ml. In cases where the addition of test item was not feasible through pipetting because of a too small volume, the corresponding test concentrations were prepared by dilution of the next higher test concentration. These mixtures were very moderately shaken. The resulting solutions were used as the test solutions in the toxicity test. Pure Daphnia medium served as blank controls.
- O2 concentration and pH were measured in the test medium for each concentration including the blank control. If the O2 concentration was too low (>5.0 mg/l required) the media was aerated by stirring. Afterwards, the media were filled into the test vessels (50 ml per vessel).
- Daphnia, aged less than 24 h and already acclimatized to the Daphnia medium, were then introduced into the test media, and the vessels were covered with a glass plate. The Daphnia were not fed during the test and the test vessels were not aerated.
semi static conditions: After 24 h, the Daphnia were transferred to the fresh test media.
- Evidence of undissolved material: Since the test item is volatile, the test solutions were prepared, separately for each test concentration, by direct addition (pipetting) of the respective quantities of test item to Daphnia medium, considering a density of about 0.904 g/ml. In cases where the addition of test item was not feasible through pipetting because of a too small volume, the corresponding test concentrations were prepared by dilution of the next higher test concentration.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISMS
- Test organism: Daphnia magna (Straus, 1820), derived from a healthy stock and not first brood progeny
- Breeding: Parental and young Daphnia held in 4 l glass aquaria (3 l medium) at 20±2 °C
- Illumination: 16 h per day
- Medium: Continuously aerated Elendt M4 medium prepared with ultra-pure water (conductivity <1.5 µS/cm)
- Feed: Suspension of Desmodesmus subspicatus in Elendt M4 medium with an optical density OD680 of about 15 units

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
not reported
Test temperature:
18–22 °C, controlled at ±1 °C
pH:
6.5 to 7.5
Dissolved oxygen:
The minimum dissolved oxygen concentration in the controls and the test vessels at the end of each 24h-period was >=6.1 mg O2/l (required >=3 mg O2/l).
Salinity:
not reported
Conductivity:
650 to 692 µS cm-1
Nominal and measured concentrations:
The concentrations of Vinyl propionate in the test medium were determined by GC-MS analysis (LOQ 0.049 mg/l) at the beginning, after 24 h in the old and the fresh media, and after 48 h of exposure. These analyses confirmed that the test item concentrations at the beginning were within 80-120% of the nominal concentrations and that the concentrations decreased over each 24 h period and did not remain within 80-120% of the nominal concentrations.
The measured concentrations of the test item at the beginning of the test were 42.5, 20.4, 8.59, 4.63 and 1.85 mg/l (85, 90, 83, 98 and 87%, respectively, of the nominal concentrations) and 31.9, 14.8, 6.36, 3.57 and 1.25 mg/l (64, 65, 62, 76 and 59%, respectively, of the nominal concentrations) after 24 h in the old media.
After renewal of the test media at 24h, the concentrations were 48.6, 23.1, 9.39, 4.47 and 2.01 mg/l (97, 102, 91, 95 and 94%, respectively, of the nominal concentrations), and 41.5, 17.8, 6.43, 3.62 and 1.30 mg/l (83, 78, 62, 77 and 61%, respectively, of the nominal concentrations) at the end of the test.
Details on test conditions:
TEST SYSTEM
- Test vessel: 50 ml flask, all-glass, with 50 ml of test medium, closed to avoid evaporation and contamination of the test solutions with dust
- Test medium: Elendt M4 medium; prepared with ultra-pure water (conductivity <1.5 µS/cm)
- Number of Daphnia: 40 individuals per test concentration, 20 per vessel
- Age: Less than 24 h
- Light: 16 h photoperiod a day, supplied by overhead white fluorescent tubes
- Temperature: 18–22 °C, controlled at ±1 °C
- pH: 6 to 9. The pH should normally not vary by more than 1.5 units in one test.
- Feed: The Daphnia are not fed during the test
- Aeration: The test vessels were not aerated during the test.
- Test type: Semi-static exposure conditions; renewal of test medium after 24 h of exposure
- Test duration: 48 h

RANGE-FINDING STUDY
Prior to the definitive test a non-GLP range finding test with nominal concentrations of 1, 10 and 100 mg/l of Vinyl propionate was performed.

EFFECT PARAMETERS MEASURED
Observed immobility (inability to swim) of the daphnids: Observations of immobile Daphnia were made after 24 and 48 h of exposure. Any abnormal behaviour or appearance was reported.
Reference substance (positive control):
yes
Remarks:
Acute reference test with potassium dichromate conducted twice a year

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
8.07 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
11.3 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
7.58 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
24 h
Dose descriptor:
EC10
Effect conc.:
11.3 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
19.8 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
24 h
Dose descriptor:
NOEC
Effect conc.:
7.39 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
After 24 h, following immobilization rates were observed: 100% at 50.0 mg/l and 32.5% at 22.7 mg/l. No significant effects (<=10% immobilization) were observed at 10.3, 4.70 and 2.13 mg/l or in the blank controls.
Based on these effects and the measured concentrations of the test item, the 24h-EC50 of Vinyl propionate to Daphnia magna was calculated to be 19.8 mg/l (95% confidence limits: 17.3–22.7 mg/l). The low effect concentration EC10 after 24h was calculated to be 11.3 mg/l (95% confidence limits: 8.38–13.5 mg/l).
The no observed effect concentration (NOEC) after 24h was determined to be 7.39 mg/l.

After 48 h, following immobilization rates were observed: 100% at 50.0 mg/l and 100% at 22.7 mg/l. No significant effects (<=10% immobilization) were observed at 10.3, 4.70 and 2.13 mg/l or in the blank controls.
Based on these effects and the measured concentrations of the test item, the 48h-EC50 of Vinyl propionate to Daphnia magna was calculated to be 11.3 mg/l (95% confidence limits: 9.21–20.2 mg/l). The low effect concentration EC10 after 48h was calculated to be 8.07 mg/l (95% confidence limits: 6.25–10.2 mg/l).
The no observed effect concentration (NOEC) after 48h was determined to be 7.58 mg/l.
Results with reference substance (positive control):
Acute ref. test with K2Cr2O7 conducted twice a year. The EC50 value for the control of sensitivity for 24 h of exposure with K2Cr2O7 was estimated to be 0.89 mg/l (29.6.2016), which lies within the recomm. range of 0.6–2.1 mg/l acc. to OECD Guideline 202.
Reported statistics and error estimates:
Therefore, the effective concentrations ECx after 24 h of exposure were assessed based on the geometric mean of the measured concentrations at 0 and 24 h; while the effective concentrations ECx after 48 h of exposure were assessed based on the arithmetic mean of the two 24-h periods’ geometric means of the measured concentrations.
Statistical analysis was performed with respect to ECx values and their 95% confidence intervals whenever possible. The statistical analysis was conducted with the software ToxRat® Standard Version 3.2.1.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
All validity criteria i.e. immobilization in the controls <=10% and O2 concentrations at the end of the test >=3 mg/L were fulfilled.
Conclusions:
The acute toxicity of Vinyl propionate (CAS no. 105-38-4) to Daphnia magna was determined in a 48 hour semi-static test according to OECD guideline 202. The median effect concentrations (EC50) of Vinyl propionate on Daphnia magna were estimated to be 19.8 mg/l and 11.3 mg/l measured concentration after 24 and 48 h of exposure, respectively. The NOEC values were determined to be 7.39 mg/l and 7.58 mg/l measured concentration after 24 and 48 h of exposure, respectively. The results of the test can be considered reliable without restriction.
Executive summary:

The median effect concentration (EC50) and the no-effect concentration (NOEC) of Vinyl propionate (CAS no. 105-38-4) to Daphnia magna were investigated under semi-static exposure conditions over a period of 48 h, following guideline OECD 202.

The test item Vinyl propionate is liquid, has a high solubility (7.52 g/l, pH of 3.5-3.9 and ca. 20 °C) and is 99.88% pure. Since the test item is volatile, the test solutions were prepared, separately for each test concentration, by direct addition (pipetting) of the respective quantities of test item to Daphnia medium.

The investigated nominal concentrations were 50.0, 22.7, 10.3, 4.70 and 2.13 mg/l.

40 individual Daphnia divided into 2 test vessels were exposed to each concentration of the test item, and 60 Daphnia divided into 3 test vessels were used as blank controls.

The concentrations of Vinyl propionate in the test medium were determined by purge and trap GCMS analysis at the beginning of the test, as well as after 24 (in the fresh and old media) and 48 h of exposure. These analyses confirmed that the concentrations of test item decreased over time and were not within 80-120% of the nominal concentrations. Therefore, the effective concentrations ECx were assessed based on the measured concentrations.

After 24 h, following immobilization rates were observed: 100% at 50.0 mg/l and 32.5% at 22.7 mg/l. No significant effects (<=10% immobilization) were observed at 10.3, 4.70 and 2.13 mg/l or in the blank controls.

After 48 h, following immobilization rates were observed: 100% at 50.0 mg/l and 100% at 22.7 mg/l. No significant effects (<=10% immobilization) were observed at 10.3, 4.70 and 2.13 mg/l or in the blank controls. The results of the toxicity of Vinyl propionate to Daphnia magna after 24 and 48 h of exposure are summarized in the following table, showing EC-values and 95% confidence limits (cl) based on the measured concentrations:

Parameter, expressed as Measured concentration (mg/l)

24 h of exposure

 EC10

 EC50

 NOEC (1)

 Estimate

11.3

 19.8

 7.39

 Lower 95%-cl

 8.38

 17.3

 -

 Upper 95%-cl

 13.5

 22.7

Parameter, expressed as Measured concentration (mg/l) 

48 h of exposure

 

 

 

 Estimate

 8.07

 11.3

 7.58

 Lower 95%-cl

6.25

 9.21

 -

 Upper 95%-cl

 10.2

 20.2

 -

cl: confidence limit

(1) : no statistical analysis; NOEC = highest concentration for which <=10% immobilization is observed

The 48 h EC50 value of Vinyl propionate (CAS no. 105-38-4) to Daphnia magna was 11.3 mg/l, based on the measured concentrations.

All validity criteria were fulfilled