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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
experimental study
Adequacy of study:
key study
Study period:
August 16, 2007 - October 11, 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD 222. Well documented. Validity criteria fulfilled.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Calcium dihydroxide
EC Number:
215-137-3
EC Name:
Calcium dihydroxide
Cas Number:
1305-62-0
Molecular formula:
CaH2O2
IUPAC Name:
calcium dihydroxide
Details on test material:
Product type: PRECAL(R) 50S
Batch no: 7025
Received: 30 January 2007
Purity active ingredient: 98.2% calcium dihydroxide
Chemical analysis: 74.4% CaO, 0.6% MgO, 0.07% SiO2, 0.05% Al2O3, 0.04% Fe2O3, 0.02% Mn3O4, 0.01% SiO3
Air jet sieving: R>90 um 4%; R>200 um 0.1%; R>630 um 0%
Laser particle size distribution: 27.3% <1 um; 50% < 1.7 um; 97% < 50 um
Expiry date: January 2009
Appearance: white powder
Water solubility (20°C): 1650 mg/l
Storage conditions: room temperature, dry conditions

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
Not applicable.

Test substrate

Vehicle:
no
Details on preparation and application of test substrate:
- approx. 24 h before test start, artificial soil was prepared
- deionized water was added to dry components to adjust water content to approx. 40 - 60 % of WHC
- test item incorporated directly into the soil by mixing with a small quantity of finely ground quartz sand (10 g of vessel), such that the required test concentration was achieved once mixed with the artificial soil

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
- Eisenia fetida andrei
- source: original breeding animals were purchased from "W. Neudorff GmbH KG", An der Mühle 3, D-31860 Emmertal
- test animals: reared under ambient laboratory conditions in the test facility
- age of animals used in the test: adult worms (approximately 3 months old with clitellum)
- weight of animals used in the test: 313 - 466 mg/worm
- feeding: weekly during first 4 weeks, by adding ground hourse manure on the soil surface (last feeding at 4 weeks)

ACCLIMATION
- period: approx. 24 h in artificial soil (with food)

Study design

Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
4 wk
Remarks:
4 weeks for adult mortality
Post exposure observation period:
4 weeks for juvenile development

Test conditions

Test temperature:
18-22 °C
pH:
test start: 6.23 - 8.17
test end: 6.05 - 7.71
Moisture:
test start: 34.8-35.0 %
test end: 34.7-35.1 %
Details on test conditions:
- light conditions: light/dark 16/8 h, artificial light (590 lx)
- food: air-dried and ground horse manure (5 g at test start)
- feeding frequency/amount: weekly, amount of manure depended on feeding activity
- test vessels: plastic, 18.3 x 13.6 x 6.4 cm, with lid pervious to air and light
- number of animals/vessel (= replicate): 10
- number of replicates/control group: 8
- number of replicates/treated group: 4
- number of animals/control group: 80
- number of animals/treated group: 40
- amount of soil/test vessel: 556 g dry weight (corresponding to approx. 750 g moist soil)
- total carbon content (%): 4.51 %
- total organic carbon content (%): 4.47 %
- light conditions:
* source: artificial light
* intensity: 590 lx
* duration: 16:8 light:dark
Nominal and measured concentrations:
nominal concentrations: 0, 250, 500, 1000, 2000, 4000 and 5000 mg test item/kg soil d.w.
Reference substance (positive control):
yes
Remarks:
Benlate

Results and discussion

Effect concentrationsopen allclose all
Duration:
4 wk
Dose descriptor:
NOEC
Effect conc.:
2 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
Ca(OH)2
Basis for effect:
reproduction
Duration:
4 wk
Dose descriptor:
EC50
Effect conc.:
4 180 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
Ca(OH)2
Basis for effect:
reproduction
Remarks on result:
other: 95% CL: 3346-4665 mg/kg soil d.w.
Duration:
4 wk
Dose descriptor:
NOEC
Effect conc.:
5 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Remarks:
Ca(OH)2
Basis for effect:
mortality
Details on results:
Validity criteria for control group:
- adult mortality after 4 weeks: <= 10 %
- number of juveniles per replicate: >= 30
- coefficient of variation of reproduction: <= 30%

- Mortality at end of exposure period: 0% in all dose groups
- Total mass of adults at beginning of test: mean between 378.1 and 384.1 mg
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: 31.8% (control), 29.1% (250 mg/kg), 28.8% (500 mg/kg), 32.8% (1000 mg/kg), 29.4% (2000 mg/kg), 26.8% (4000 mg/kg), 22.6% (5000 mg/kg)
- No. of offspring produced: mean numbers:129.5 (control), 123 (250 mg/kg), 126.5 (500 mg/kg), 125.3 (1000 mg/kg), 118 (2000 mg/kg), 77.3 (4000 mg/kg), 32.8 (5000 mg/kg)
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- Relevant effect levels: The number of juveniles was reduced by 67% and 100% compared to control at concentrations of 5 and 10 mg Benlate/kg soil d.w., respectively.
Reported statistics and error estimates:
- probit analysis according to the maximum likelihood methods was used for the calculation of EC50 (software ToxRat Professional 2.09)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Adult mortality: ≤ 10% (being 0% after 4 weeks). Number of juveniles per replicate: ≥ 30 (being 158, 144, 97, 128, 119, 135, 109 and 146). Coefficient of variation of variation of reproduction: ≤ 30% (being 15.8%).
Conclusions:
Calcium dihydroxide did not show significant adverse effects on survival and growth of the earthworm Eisenia fetida in artificial soil up to 5000 mg Calcium dihydroxide/kg soil dry weight, i.e. the highest rate tested.
The test item showed statistically significantly adverse effects on reproduction at 4000 and 5000 mg Calcium hydroxide/kg soil d.w. Therefore, the NOEC for reproduction was determined to be 2000 mg Calcium dihydroxide/kg soil dry weight. The EC50 for number of juveniles was calculated to be 4180 mg Calcium dihydroxide/kg soil dry weight.
Executive summary:

A study was conducted exposing forfour weeks the earthworm, Eisenia fetida, to a concentration range of 250-5000 mg/kg soil d.w. of Calcium dihydroxide. The test followed the OECD guideline 222 under GLP standards and validity criteria were satisfied. Results showed not significant adverse effects on survival and growth. However, statistically significantly adverse effects on reproduction were found at the concentrations of 4000 and 5000 mg/kg soil d.w. Therefore, the NOEC for reproduction was determined to be 2000 mg/kg soil dry weight. The EC50 for number of juveniles was calculated to be 4180 mg/kg soil dry weight.

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