Registration Dossier

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study

Data source

Reference
Reference Type:
publication
Title:
Toxicity of eight polycyclic aromatic compounds to red clover (Trifolium pratense), ryegrass (Lolium perenne), and mustard (Sinapsis alba)
Author:
Sverdrup LE, Krogh PH, Nielsen T, Kjcr C, Stenersen J
Year:
2003
Bibliographic source:
Chemosphere, 53, 993-1003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)
Principles of method if other than guideline:
Comparative study including 4 aromatic and and 4 heteroaromatic compounds.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Phenanthrene
Source: Sigma-Aldrich (Steinheim, Germany)
Purity: >96 %
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Vapour pressure: ~ 0.016 Pa (25 °C)
- Water solubility: ~ 1.3 mg/L (25 °C)
- log Pow: 4.5 - 4.6

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Initial concentration in test soil for verification of test-substance levels

Test substrate

Vehicle:
yes
Details on preparation and application of test substrate:
- Method of application to soil: Test substance dissolved in acetone, diluted from a stock solution:
250 ml acetone solution was mixed into 1.25 kg soil. Pure acetone was used for the control test. Solvent-free controls were also included.
- Vehicle: Acetone
- Evaporation of vehicle before use: The solvent was evaporated from the treated soil (spread on glass plates) in a fume head for 24 h.

Test organisms

open allclose all
Species:
Sinapis alba
Plant group:
Dicotyledonae (dicots)
Details on test organisms:
- Common name: Mustard
- Plant family: Brassicaceae
- Variety: no data
- Source of seed: Ove Rassmussens Planteskole (Silkeborg, Denmark)

Prior to test start dameged/ discoloured seeds were rejected
Seeds of similar size were selected for the experiment
Species:
Trifolium pratense
Plant group:
Dicotyledonae (dicots)
Details on test organisms:
- Common name: Red clover
- Plant family: Fabaceae
- Variety: no data
- Source of seed: DLF Trifolium (Randers, Denmark)

Prior to test start dameged/ discoloured seeds were rejected
Seeds of similar size were selected for the experiment
Species:
Lolium perenne
Plant group:
Monocotyledonae (monocots)
Details on test organisms:
- Common name: Perennial ryegrass
- Plant family: Gramineae
- Variety: no data
- Source of seed: DLF Trifolium (Randers, Denmark)

Prior to test start dameged/ discoloured seeds were rejected.
Seeds of similar size were selected for the experiment.

Study design

Test type:
early seedling growth toxicity test
Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
19 d
Post exposure observation period:
no data

Test conditions

Test temperature:
Night: 15 °C, day ~25 °C, sometimes higher
pH:
Soil pH: 6.2
Moisture:
Test soils were hydrated to 65 % of the water holding capacity with water (200 ml/kg soil).
Details on test conditions:
TEST SYSTEM
- Testing facility: Growth chamber placed in a green house
- Test container: Transparent cylinder made of hard plastics (35 cm high, inner diameter 9.5 cm), closed at the top and bottom with lids.
The upper lid was perforated with one hole.
- Amount of soil: 300 g wet weight per test container
- No. of seeds per container: 5
- No. of plants per replicate per dose: 5
- No. of replicates per treatment group: 4
- No. of replicates per control: 5
- No. of replicates per vehicle control: 5
- Plant density: ~71 cm2 / 5 seeds = ~14 cm2/seed; 300 g soil wet weight/5 seeds = 60 g/seed

All three species were tested simultaneously.

SOURCE AND PROPERTIES OF THE ARTIFICIAL SOIL:

Danish agricultural soil (Askov, Jutland): Sandy loam
- Coarse sand (0.2 – 2 mm) 38.4 %,
- fine sand (0.063 – 0.2 mm) 23.6 %,
- coarse silt (0.02 – 0.063 mm) 10.0 %,
- fine silt (0.002 – 0.02 mm) 12.3 %,
- clay (<0.002 mm) 13 %, humus 2.8 %
Organic carbon content: 1.6 %
Soil pH: 6.2
Density: 1.135 g/cm3
Cation exchange capacity: 8.14 meq/100 g

Pretreatment of the soil prior to use: Drying at 80 °C for 24 h, sieving: (2 mm mesh)

NUTRIENT MEDIUM (if used)
- Description:

GROWTH CONDITIONS
- Photoperiod: 16 h light, 8 h darkness alternately
- Light source: Cultivation lamps (400 W, 310 - 780 nm)
-Approximate photoflux density: 300 µE/m2/s on soil surface

- Day/night temperatures: Night: 15 °C, day ~25 °C, sometimes higher

EFFECT PARAMETERS MEASURED: Dry weight, fresh weight
Number of germinated seed by counting the seedlings that protruded above the soil surface

- Phytotoxicity rating/ harvest: 14 d after which 50 % of the seeds had emerged in the control samples

VEHICLE CONTROL PERFORMED: yes

Nominal and measured concentrations:
Nominal: 1, 10, 100, and 1000 mg/kg soil d.w.
Confirmation by analysis: 0.9, 9.9, 114, 1100 mg/kg soil d.w.

Results and discussion

Effect concentrationsopen allclose all
Species:
Sinapis alba
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
ca. 13 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Remarks on result:
other: Estimation, related to 2 % organic carbon (standard)
Species:
Trifolium pratense
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
ca. 13 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Remarks on result:
other: Estimation, related to 2 % organic carbon (standard)
Species:
Sinapis alba
Duration:
21 d
Dose descriptor:
other: EC20
Effect conc.:
77 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Remarks on result:
other: 95% C.I. 41 - 110 mg/kg soil dw
Species:
Sinapis alba
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
480 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Species:
Trifolium pratense
Duration:
21 d
Dose descriptor:
other: EC20
Effect conc.:
37 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Remarks on result:
other: 95% C.I. 22 -52 mg/kg soil dw
Species:
Trifolium pratense
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
79 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Species:
Lolium perenne
Duration:
21 d
Dose descriptor:
other: EC20
Effect conc.:
300 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Species:
Lolium perenne
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
760 mg/kg soil dw
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth
Remarks:
- fresh weight
Details on results:
No effect on seed germination observed at any exposure level: => LC50 supposed >> 1000 mg/kg soil d.w.
The NOEC values are estimates, as no effects data below EC20 were documented:
The results of the study indicate that NOECs for the tested PAHs to terrestrial plants is 10 mg/kg dw soil.
(except for fluoranthene which is supposed to have a NOEC of approx. 100 mg/kg dw.)
Reported statistics and error estimates:
The LC50 was determined using the Probit method (with SAS/STAT software).
EC20- and EC50 values were estimated by linear interpolation of the dose-response curve, confidence intervals by the regression procedure of SAS/STAT.
NOECs were determined using ANOVA and Dunnett´s procedure (at 5-% significance level).

Applicant's summary and conclusion