Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

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:
2002-04-09 to 2002-07-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Guideline study. The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 10 and 100 mg/L

- Sampling method: An aliquot of freshly prepared test medium was taken from each test concentration before filling the test vessels. A further aliquot was also taken from the combined four replicates of each treatment at the end of the test. Samples of the freshly-prepared test media were only analysed if the samples taken at the end of the test showed conentrations significantly different from expected.

- Sample storage conditions before analysis: Samples were stored at -20ºC prior to analysis.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: A 100 mg/L nominal stock solution concentration was prepared by intense stirring for 30 minutes. The stock solution was diluted to produce a further nominal concentration of 10 mg/L.

- Controls: Dilution water

- Evidence of undissolved material (e.g. precipitate, surface film, etc): none reported
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM

- Strain: IRCHA

- Source: LPT Laboratory Culture

- Age at study initiation (mean and range, SD): 6-24 hours

ACCLIMATION

- Acclimation period: at least one week

- Acclimation conditions (same as test or not): yes

- Type and amount of food: algae (Scenedesmus subspicatus) plus a small quantity of sewage from the aerated phase of treatment.
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Hardness:
250 mg/L as CaCO3
Test temperature:
19-21ºC
pH:
7.7-8.1
Dissolved oxygen:
>/=80% ASV
Salinity:
not applicable
Nominal and measured concentrations:
Nominal concentrations: 0(Control), 10 and 100 mg/L

Measured DOC concentrations were within +/-20% of the theoretical values.

The test results are presented and interpreted with reference to the nominal concentrations.
Details on test conditions:
TEST SYSTEM

- Test vessel:

- Type (delete if not applicable): open

- Material, size: glass, 38 mm diameter, 60 mm tall, 50 mL volume

- Aeration: none

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: aerated reconstituted water

- Alkalinity: 0.8 mmol/L

- Ca/mg ratio: 4:1

- Culture medium different from test medium: no

- Intervals of water quality measurement: Start and end ot test


OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 16 h light/8 h dark

- Light intensity: 500 Lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mobility after 24 and 48 hours


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 10
Reference substance (positive control):
no
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis products
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
but exposure is to hydrolysis products
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 85 mg/L
Nominal / measured:
nominal
Conc. based on:
other: molecular weight corrected value
Remarks:
exposure is to hydrolysis products
Basis for effect:
mobility
Details on results:
- Immobilisation of control: 5%

- Other adverse effects control: none
Reported statistics and error estimates:
The level of immobilisation in the highest treatment was insufficient to determine an EC50 value. The NOEC was determined directly from the raw data.

Table 1. Test results

 Nominal test concentration (mg/L)  Mean percentage immobilisation after 24 hours  Mean percentage immobilisation after 48 hours
 0 (Control)  5  5
 10  0  0
 100  15  20

Table 2. Results of analysis of test media

 Nominal test concentration (mg/L)  Theoretical DOC concentration (mg/L)  Actual DOC concentration at the end of the test (mg/L)
 10  3.9  4.3
 100  39.4  38
Validity criteria fulfilled:
yes
Conclusions:
A 48-hour EC50 value of >100 mg/L and NOEC of 10 mg/L have been determined for the effects of the test substance on mobility of Daphnia magna. The results are expressed relative to nominal concentrations of the substance. However it is likely that the test organisms were primarily exposed to the hydrolysis products of the substance.

Description of key information

Short-term toxicity to invertebrates: 48 hour EC50 >100 mg/l (nominal) (highest concentration tested) (OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)). The observations in this study are attributed to the exposure of test organisms to the hydrolysis products in the test system. The result may be expressed in terms of concentration of the hydrolysis product: 48 hour EC50 >85 mg/l as 3-chloropropyl(methyl)silanediol.

Key value for chemical safety assessment

Additional information

 A 48 hour EC50 value of >100 mg/l has been determined for the effects of the test substance on mobility of Daphnia magna based on nominal test concentrations. Due to the rapid hydrolysis rate of the test substance it is very likely that the test organisms were exposed to the hydrolysis products of the substance rather than the parent substance. The results may be expressed in terms of concentration of the hydrolysis product, 3-chloropropyl(methyl)silanediol, by applying a molecular weight correction: (MW of silanol = 154.67 / MW of parent = 182.72) * [CONCENTRATION OF PARENT = >100] = >85 mg/l.