Chloroacetone

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:

2021-03-02 to 2021-03-26

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 (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: At the start, samples were taken after preparation of each concentration level and the control and analyzed. At the end of the renewal (24 hours) and the exposure (48 hours), samples of the old media were taken from the test vessels.
- Sampling schedule: at the start of exposure and at the renewal of the test solutions (0 and 24 hours) as well as in the 24-hours old media at the renewal and at the end of the exposure (24 and
48 hours)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test solutions were prepared using a stock solution. For the stock solution 10.0 mg test item/L were freshly prepared with dilution water. For preparation the density was taken into account. The solution was agitated until the solution was visually clear (approx. 1 minute).
- Controls: Dilution water without test item incubated under the same conditions as the test groups. In addition, a reference test with potassium dichromate was separately conducted as an acute immobilization test in Elendt M4 medium under static conditions with a test duration of 24 hours once per month in order to prove the validity of the test system and test conditions at the test facility.
- Test concentration separation factor: 2.2
- Evidence of undissolved material: no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation: less than 24 hours old
- Stage and instar at study initiation: juvenile, no first brood progeny
- Method of breeding: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 +/- 2 °C, 16 hours illumination, light intensity of max. 1500 lux; Elendt M4, according to OECD 202; daphnids were fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus (algae cultured at the test facility).
- Source: continuous laboratory cultures; originally obtained from Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany
- Feeding during test: no

ACCLIMATION
Acclimatization was not necessary, because the composition of the dilution water is equivalent to the culture medium.

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS:
Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period were used for the test. No first brood progeny was used for the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Test temperature:

18 - 22 °C, constant within ± 1 °C

pH:

6.57-8.88 (treatments)

Dissolved oxygen:

8.32 - 9.33 mg/L

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

nominal: 1.76, 0.800, 0.364, 0.165, 0.0750, 0 (negative control) mg/L; Measured: 1.59, 0.728, 0.338, 0.152, 0.0637, < LOQ (negative control) mg/L (geom. mean measured)

Details on test conditions:

TEST SYSTEM
- Test vessel: flasks
- Type: closed
- Material, size, headspace, fill volume: Sealed glass flasks (4.5 (ID) x 9.5 (H) cm) with screw were used and filled up to the top with the test solutions.
- Volume of solution: approximately 130 mL
- Aeration: no
- Renewal rate of test solution: after 24 hours of exposure
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to OECD 202

OTHER TEST CONDITIONS
- Adjustment of pH:no
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: diffuse light, light intensity of max. 1500 lx

EFFECT PARAMETERS MEASURED: immobility of daphnids after 24 and 48 hours

RANGE-FINDING STUDY
- Test concentrations: 10, 1 and 0.1 mg/L along with a negative control
- Results used to determine the conditions for the definitive study: yes

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

0.728 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 1.59 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.369 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Limits: 0.338 – 0.728 mg/L

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

0.817 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Limits: 0.366 – 1.58 mg/L

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.346 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Limits: 0.190 – 0.671 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

1.16 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Limits: 0.749 – 1.59 mg/L

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: not reported
- Other biological observations: none
- Mortality of control: no
- Other adverse effects control: no
- Immobilisation of control: no
- Abnormal responses: no
- Any observations that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC40 (24 h) = 1.94 mg/L (nominal) (CL: 1.00 - 4.00 mg/L)

Reported statistics and error estimates:

EC10/50 values were determined using sigmoidal dose-response regression. 95 % confidence limits for the EC10 / 50-values after 24 hours and for the EC10-values after 48 hours were calculated from the standard error and the t-distribution. The confidence limits for the EC50-values after 48 hours was estimated empirically from the observed immobilization rates.

Table 1: Immobilization Rates after 24 and 48 hours of Exposure (n = 20, divided into 4 replicates with 5 daphnids each)

Geometric mean measured concentration of the test item [mg/L]	IMMOBILIZATION [%]
	24 hours					48 hours
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
1.59	80	80	100	80	85	100	100	100	100	100
0.728	0	0	20	0	5	100	100	100	100	100
0.338	0	0	0	0	0	0	0	20	0	5
0.152	0	0	0	0	0	0	0	0	0	0
0.0637	0	0	0	0	0	0	0	0	0	0

 

Table 2: Measured Concentrations of the Test Item during the Definitive Test

Sampling sate	Fresh media, 0 hours		Old media, 24 hours
Nominal concentration of the test item [mg/L]	Meas. Conc. [mg/L]	%	Meas. Conc. [mg/L]	%
1.760	1.68	95	1.46	83
0.800	0.776	97	0.64	80
0.364	0.375	103	0.286	78
0.1.65	0.175	106	0.129	78
0.075	0.0746	99	0.0583	78
Control	< LOQ		< LOQ
QC	112%		99%^1)

Meas. conc.= measured concentration of the test item, dilution factors taken into account
% = percent of the nominal concentration of the test item
LOQ = limit of quantification of the analytical method (1.5 μg/L of the test item)
¹⁾ = QC for Old media (24 hours) and Fresh media (24 hours)
QC = Procedural recovery on 10 x LOQ-level, % recovery calculated to weighed amount of the test item, mean value 104 %

Validity criteria fulfilled:

yes

Conclusions:

In an Acute Immobilisation Test with Daphnia magna according to OECD 202 the 48 hour EC50 of the test item was determined to be 0.369 mg/L (95% CL: 0.338 – 0.728) based on geom. mean measured concentrations.

Executive summary:

The effects of the test item to aquatic invertebrates were assessed in an Acute Immobilisation Test with Daphnia magna according to OECD 202. The study was conducted under semi-static conditions in closed test vessels without headspace over a period of 48 hours. Five concentrations of the test item (nominal: 0.0750 to 1.76 mg/L) prepared from a stock solution of 10.0 mg test item/L in a geometric series with a separation factor of 2.2 were tested. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control. The concentrations of the test item were analytically verified via GC-MS in the fresh media at the start of the exposure and at the renewal of the test solutions (0 and 24 hours) and in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours) in all concentration levels and the control. The measured concentrations of the test item in the fresh media were in the range of 94 to 106 % of the nominal values at the start of the exposure (0 hours) and at the renewal (24 hours). The measured concentrations of the test item in the old media at the renewal and at the end of the test (24 and 48 hours) were in the range of 72 to 94 % of the nominal values. Therefore, biological results are based on geom. mean measured concentrations. All validity criteria of the guideline were fulfilled. As a result, the 48 hour EC50 of the test item was determined to be 0.369 mg/L (95 % CL: 0.338 – 0.728 mg/L).

Description of key information

In an Acute Immobilisation Test with Daphnia magna according to OECD 202 the 48 hour EC50 of the substance was determined to be 0.369 mg/L (95 % CL: 0.338 – 0.728) based on geom. mean measured concentrations (reference 6.1.3-1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

0.369 mg/L

Additional information

The effects of the test item to aquatic invertebrates were assessed in an Acute Immobilisation Test with Daphnia magna according to OECD 202. The study was conducted under semi-static conditions in closed test vessels without headspace over a period of 48 hours. Five concentrations of the test item (nominal: 0.0750 to 1.76 mg/L) prepared from a stock solution of 10.0 mg test item/L in a geometric series with a separation factor of 2.2 were tested. Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration level and the control. The concentrations of the test item were analytically verified via GC-MS in the fresh media at the start of the exposure and at the renewal of the test solutions (0 and 24 hours) and in the 24-hours old media at the renewal and at the end of the test (24 and 48 hours) in all concentration levels and the control. The measured concentrations of the test item in the fresh media were in the range of 94 to 106 % of the nominal values at the start of the exposure (0 hours) and at the renewal (24 hours). The measured concentrations of the test item in the old media at the renewal and at the end of the test (24 and 48 hours) were in the range of 72 to 94 % of the nominal values. Therefore, biological results are based on geom. mean measured concentrations. All validity criteria of the guideline were fulfilled. As a result, the 48 hour EC50 of the test item was determined to be 0.369 mg/L (95 % CL: 0.338 – 0.728 mg/L).