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Ecotoxicological information

Toxicity to terrestrial plants

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Administrative data

Endpoint:
toxicity to terrestrial plants: long-term
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2001-05-09 to 2001-11-08
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP-Guideline study. According to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Landesamt fpr Pflanzenbau und Pflanzenschutz, Rheinland-Pfalz, Germany

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Doucil 4A (former Wessalith 4000)
- Related CAS number: 1318-02-1
- Framework: monoclinic
- Molecular formula: Na12[(AlO2)12(SiO2)12].27H2O
- Physical state: white powder
- Analytical purity: no data
- Lot/batch No.: 494
- Storage condition of test material: at room temperature, in closed package

Sampling and analysis

Analytical monitoring:
no

Test substrate

Vehicle:
no
Details on preparation and application of test substrate:
To avoid deviation effects due to resulting differences in organic matter of the soil, the test substance was mixed with the Standard Soil 3A instead of sand. Composition of the soil: 40% Standard Soil 3A (LUFA Speyer; organic carbon content 3.1%, 36.4% particles 0.02 mm, max. particle size 2 mm, density 1140 g/1000 mL, pH 7.1), 40% sand, 20% deionized water.

Test organisms

Species:
Raphanus sativus
Plant group:
Dicotyledonae (dicots)
Details on test organisms:
purchased from a natural food store, belonging to the same size class

Study design

Test type:
other: seedling emergence and seedling growth test
Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
23 d

Test conditions

Test temperature:
20 +/- 2 °C
pH:
adjusted to 6.5 with HCl
Moisture:
60-75%
Nominal and measured concentrations:
Following concentrations were tested: 0, 0.5, 1.5, 5 and 15 g/kg.

Results and discussion

Effect concentrationsopen allclose all
Species:
Raphanus sativus
Duration:
23 d
Dose descriptor:
EC50
Effect conc.:
4 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Species:
Raphanus sativus
Duration:
23 d
Dose descriptor:
LC50
Effect conc.:
5 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
seedling emergence
Species:
Raphanus sativus
Duration:
23 d
Dose descriptor:
NOEC
Effect conc.:
1 500 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
phytotoxicity

Any other information on results incl. tables

85% of the control seeds produced healthy seedlings exhibiting normal growth throughout the test.
EC50 for growth was determined as 4 g/kg, LC50 for emergence was 5 g/kg and NOEC growth was stated as 0.5 g/kg.

% weight per plant compared to control (mean 94.9 mg):
0.5
       92% (mean 87.4 mg)
1.5
       73% (mean 69.1 mg)
5
         57% (mean 54.1 mg)
15
         0% (mean 0)

% emergence compared to control (mean 85% emerged seeds):
0.5
      100% (mean 85% emerged seeds)
1.5
      100% (mean 85%)
5
         65% (mean 55%)
15
         0% (mean 0%)

At higher concentrations (15 g/kg), phytotoxic effects could be observed. Some of the seedlings showed a little emergence, but most of them could not unfurl even the cotyledon. If initial germination (until unfurling of the cotyledon) occurred completely, effect on growth seems to be a function of time only. Seeds in the control emerged significantly earlier than in treatments.
However, the effects seem to be due to the water availability within the soil. The soil with the test substance incorporated was very dense, i.e. the resulting mixture hardens strongly so that the seeds are not able to penetrate the soil. So the phyotoxic effects seem to depend on the physical properties of the test substance. At concentrations of 1.5 g/kg and below, no phytotoxic effects could be determined.

Applicant's summary and conclusion