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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
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:
OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
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.