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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12 March - 17 May 1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The study was performed according to OECD TG 202 and according to GLP principles. However, the analytical results were very variable and considered not reliable. This is probably due to the direct loading of the test substance to the test media. In this study, also physical effects play a role due to undissolved particles. No data was present on any positive control substance tested.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
yes
Remarks:
: no info on positive control
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): E-326 catalyst
- Substance type: fine grey/green powder
- Physical state: solid
- Analytical purity: 96%
- Composition of test material, percentage of components: 29.20% vanadium; P/V mole ratio 1.08; Zn/V ratio 0.00036; V oxidation state 4.18
- Purity test date: not indicated
- Lot/batch No.: 326-104
- Expiration date of the lot/batch: not indicated
- Stability under test conditions: not indicated
- Storage condition of test material: at ambient temperature in original container
- Other: the substance is identified as Trilobe III catalyst composite of E326-104. The material is milled and passed through a 40 mesh sieve (i.e. ca. 425 µm), so the particle size of the material is <425 µm. Tablet weight: 0.046 g. Tablet length: 4.06 mm. Surface area: 23 m2/g. Bulk density 0.75 g/cm3

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
The test media were prepared by direct addition of the appropriate weights of the test material to dilution water (i.e. blend of tap water filtered through activated carbon and tap water softened and treated by reverse osmosis). They were treated by sonication for 10 min and then shaken for 1 h before use. No pH adjustment and no filtration to remove undissolved particles.

Test organisms

Test organisms (species):
Daphnia magna

Study design

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

Test conditions

Nominal and measured concentrations:
Nominal exposure concentrations (based on total test material): 0.3, 0.6, 1.25, 2.5, 5.0 and 10 mg/L.

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
0.658 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
element
Remarks:
V (filtered 2 µm)
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
2 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat. (dissolved fraction)
Remarks:
filtered (2 µm)
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (total fraction)
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
0.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (total fraction)
Basis for effect:
mobility
Remarks on result:
other: Measured total concentration 0.173 mg/L

Any other information on results incl. tables

At the highest concentration tested (i.e. 10 mg/L) 50% of the daphnids were immobile. At this concentration approx. 20% of the substance was analytically determined after filtration (2 µm). Analysing the concentration of unfiltered samples at 0 and 48 hours showed a difference (12.3 mg/L and 2.2 mg/L, respectively) which was not shown in the filtered samples.

Achieved concentrations in filtered samples were lower than intended (between 6 - 58% of nominal). Measured levels in unfiltered samples ranged from 32 - 123% of nominal but showed a dose-related trend. After 48h, no test material was detected at the three lowest levels. At 2.5, 5 and 10 mg/L measured concentration in filtered samples had been maintained or increased. Measured values for unfiltered samples at these levels showed a decrease.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In this static acute Daphnia test, the 48h-EC50 was found to be 10 mg/L, based on the nominal concentration of the test material. The analytical determination of the test substance at 0 and 48h of filtered and unfiltered samples is very variable and therefore considered not reliable. The variability is probably caused by the direct loading of the test material to the test media.