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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:
August-September 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: in accordance with guidelines

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
other: EC 440/2008- Council regulation
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Algea Fert Solid K+
- Substance type: fertilizer ( algal extract)
- Physical state: solid, black micro-flakes
- Lot/batch No.: 00680
- Expiration date of the lot/batch: March 2012
- Stability under test conditions: Stable under suitable storage conditions.
- Storage condition of test material: original tightly-closed containers in well- ventilated place.

Test solutions

Vehicle:
no
Details on test solutions:
The test medium was prepared as follows: prior to the start of the test, a solution of 100 mg/L was prepared by direct weighting into reconstituted water (0.0256 g of test item into 250 mL of reconstituted water). The obtained solution appeared light-brown and it was manually mixed to achieve the totally solubilisation of test item.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: originally supplied by the Italian Health Department (Istituto Superiore di Sanità) in September 2004. Since that time, the clone has been bred in ChemService laboratories in reconstituted water with the same characteristic to the water used in the tests (as for pH, main ions, and total hardness) and under temperature and light conditions identical to those of the tests.
- Age at study initiation : 6-24 hours old
- Feeding during test: none
- Food type, amount and frequency: The daphnia breeding was daily fed with a fixed amount (300.000 cells/mL) of green algae Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum) cultivated in the ChemService Laboratory and with a suspension of the yeast Saccharomyces cerevisiae.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
Water Hardness: 140 - 250 mg/L as CaCO3
Test temperature:
The incubation temperature was measured twice a day during the course of the study by the mean of a digital thermometer. The measured values ranged between 21.2 and 21.7 °C during the test period.
Photoperiod: 16 hours light and 8 hours darkness daily photoperiod with a light intensity within the range 385 -410 Lux.
pH:
The pH of the control (test medium without test item) was 7.36 and the pH of test item solution immediately after preparation was 7.51, therefore, the pH of the test medium was not adjusted before the start of the test. The pH did not vary by more than 0.08 unit during the test, as required in the OECD’s guideline
Dissolved oxygen:
During the test period, the dissolved oxygen concentrations in the test solution and the negative control were always greater than 6.0 mg/L , according to guideline that provided a minimum oxygen concentration of 3.0 mg/L.
Salinity:
CaCl2 x 2H2O : 2.0 mmol/L (= 294 mg/L)
MgSO4 x 7H2O: 0.5 mmol/L (= 123 mg/L)
NaHCO3: 0.75 mmol/L (= 65 mg/L)
KCl: 0.075 mmol/L (= 5.8 mg/L)
Alkalinity:0.8 mmol/L
Ratio of Ca : Mg = 4 : 1 (based on molarity), Na : K= 10 : 1 (based on molarity)
Nominal and measured concentrations:
100 mg /L nominal
Details on test conditions:
The test concentration was chosen based on the results of a pre-test (range-finding test), which was not performed in compliance with the GLP Regulations. The study was carried out at the nominal concentration of 100 mg/L, moreover a negative control with reconstituted water only was also tested.
The test was performed in 50 mL glass beakers filled with 40 mL of test medium. The beakers were covered with glass plates to reduce the loss of water and to avoid the entry of dust into the solutions. The test vessels were labelled with the ChemService study number and all necessary additional information to ensure unmistakable identification.
For each test concentrations and for the control, 20 daphnids were used divided into four replicates of five daphnids each. The daphnids were randomly distributed to the test vessels at initiation of the test. The daphnid’s loading rate was greater than one daphnid per 2 mL of test solution.
The test water was aerated prior to the start of the study until oxygen saturation was reached. During the test period, test water was not aerated.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
IC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
In the negative control no immobilization was observed and no daphnid was found to be trapped on the surface water at the end of the test period. These values comply with the validity criteria of the test, that provide a maximum immobilization and/or a maximum number of daphnids trapped in to water surface of 10% in the control medium at the end of the test.

The NOEC (highest concentration tested without toxic effects after the exposure period) was determined was equal to the nominal tested concentration, 100 mg/L, at both the observation times. Given the nature of limit test, the LOEC and the 48-h IC50 could not be determined, but, according to the results, were determined to be greater than the nominal concentration tested (i.e., IC50 > 100 mg/L).

No remarkable observations were made concerning the appearance of the test medium. The test medium was a light-brown solution throughout the test duration.
Results with reference substance (positive control):
See Table 1 above reported.
Reported statistics and error estimates:
The results were analyzed for significant differences from control with the Fisher’s Exact test (α = 0.05) by the mean of CETIS elaboration software v1.026D.

Any other information on results incl. tables

Table 2      Lethal effect of Algea Fert Solid K+ toDaphnia magna

Nominal test item concentration

[mg/L]

No. of
Daphnia
tested

No. of immobilized
Daphnia

% of immobilized
Daphnia

24 h

48 h

24 h

48 h

0 (negative control)

20

0

0

0

0

100.0

20

0

0

0

0

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
In the control not more that 10% of the daphnids should have been immobilised. The oxygen concentration at the end of the test should be ≥ 3 mg/L in control and in the test vessels. For the first criterion, not more than 10 percent of the control daphnids
Conclusions:
The test item Algea Fert Solid K+ caused no adverse effect to Daphnia magna after 48-hours exposure at a nominal concentration of 100 mg/L under static conditions.
The NOEC, LOEC and IC50 values after 24 and 48 h, calculated based on nominal concentrations were as follows:
NOEC 100 mg/L
LOEC > 100 mg/L
IC50 > 100 mg/L.
Executive summary:

The acute toxicity of the test item Algea Fert Solid K+ toDaphnia magna was determined in a 48‑hour static test according tothe OECD Guideline for Testing of Chemicals, No. 202 (2004) and to Council Regulation EC 440/2008 (C.2).

 For this purpose, juvenile daphnids (<24 hours old at initiation of the test) were exposed to an aqueous test medium containing the test item at the only nominal concentration of 100.0 mg/L. The exposed organisms were checked for immobilization 24 and 48 hours after test initiation.

The pH of the control (test medium without test item) was 7.36 and the pH of test item solution immediately after preparation was 7.51, therefore, the pH of the test medium was not adjusted before the start of the test.

 The room temperature was in the range 21.2 –during the test period, according to the OECD’s recommended range (20 ± 2 °C).

Light intensity during the 48 hours of test period was in the range 385-410 Lux, within the range 200-1500 Lux.

 At the end of test period, in the negative control no immobilization was observed and no daphnid was found trapped on the test water surface. These values comply with the specified validity criterion that immobilization in the negative control group should not exceed 10% at the end of the test.

 No immobilization was observed in the test item medium after 24 and 48 hours, therefore the NOEC (highest concentration tested without toxic effects after the exposure period) of Algea Fert Solid K+ to Daphnia magna was determined to be equal to the nominal tested concentration of 100.0 mg/L.

 Based on the observed effects, the LOEC and the 48-h IC50were determined to be greater than the tested concentration, 100.0 mg/L.