1-Propanone, 2-methyl-1-[4-(methylthio)phenyl]-

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Study period:

From December 5, 1991 to January 13, 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study design appears to follow EU method C.2 with deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

No evidence that test concentrations were maintained during exposure.

GLP compliance:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): TK 13110 (Generic/Trade name: CG 21-1201)
- Batch No.: 1197
- Expiration date of the lot/batch: 09/93
- Storage condition of test material: room temperature
- Purity: 98.3%
- Physical state: white solid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

Stock solutions:
3 g test substance were mixed with 18 g from an aqueous solution containing 0.4% Arkopal (alkylphenol-polyglycol-ether) by means of a marble-mill during about 24 hours. 1 mL from this mixture was mixed with and made up to 100 mL with water making dilution 1:100.

Test concentrations:
- Nominal: 1,8, 3.2, 5.8, 10 and 18 mg test substance/L.
- Controls: Blank: water
Vehicle: 0.643 mg Arkopal/L.
Calculated amounts of the dilution 1:100 to produce the desired test concentrations were given into the water and were homogeneously distributed.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Common name: Daphnia magna
- Strain: Straus 1820
- Source: CIBA-GEIGY Ltd., testing facility
- Feeding during test: none
- Age at study initiation (mean and range, SD): 6-24 h at the start of the test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

240 mg CaCO3/l

Test temperature:

20+/-1°C

pH:

7.7 - 7.8

Dissolved oxygen:

98 - 100%

Salinity:

Freshwater

Nominal and measured concentrations:

1.8, 3.2, 5.8, 10, 18 mg/l (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers covered with watch glasses (100 mL solution per beaker)
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water
- Intervals of water quality measurement: 0 and 48 hours
- Reconstituted water containing: 65 mg NaHCO3, 294 mg CaCl2.2H2O, 123 mg MgSO4.7H2O, 6 mg KCl in 1000 mL bidistilled water.
The water was aerated with clean air for at least 24 hours before use.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours fluorescent light daily
- Light intensity: approximately 1500 lux

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Observed values

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Remarks:

calculated

Effect conc.:

14 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limit: 12 - 16 mg/l

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Observed values

Effect concentrations 4

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Immobilization in controls: no immoblization in blank and vehicle controls

Results with reference substance (positive control):

No reference substance control

Reported statistics and error estimates:

The EC50 values were calculated according to BERKSON, JASA 48 (1953), 569-599.
EC values were graphically determined on gausso-logarithmic probability paper.

Any other information on results incl. tables

Values are based only on nominal concentrations.