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Ecotoxicological information

Toxicity to terrestrial plants

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Reference
Endpoint:
toxicity to terrestrial plants: short-term
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
12 OCT - 16 DEC 1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP - guideline study with acceptable restrictions
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)
Deviations:
yes
Principles of method if other than guideline:
The test method was modelled after OECD guideline 208 but adapted to the gaseous nature of the test substance. Thus, the substance was not mixed with soil but the plants were exposed to the gas in closed chambers. In contrast to the guideline only the effect was only tested with two plant species. Two assays were conducted. In a first assay both plant species were exposed. In the second assay only Lepidum sativum was exposed to the substance.
GLP compliance:
yes
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 10 ppmv and 100 ppmv nominal
- Sampling method: samples for gas chromatographic analysis of ethylchlorid within the gas phase were taken from the influent and effluent
Vehicle:
no
Species:
Avena sativa
Plant group:
Monocotyledonae (monocots)
Details on test organisms:
- Common name: oat
- Plant family: Poaceae
- Source of seed: Hüls Gartenbaubetrieb
Species:
Lepidum sativum
Plant group:
Dicotyledonae (dicots)
Details on test organisms:
- Common name: garden cress
- Plant family: Brassicaceae
- Source of seed: Hüls Gartenbaubetrieb
Test type:
vegetative vigour test
Study type:
laboratory study
Substrate type:
natural soil
Limit test:
no
Total exposure duration:
17 d
Test temperature:
Assay 1: 20 - 26 °C
Assay 2: 23 - 29 °C
pH:
6.0
Moisture:
approximately 60% of maximum water holding capacity
Details on test conditions:
TEST SYSTEM
- Testing facility: Hüls AG, Marl, Germany
- Test container (type, material, size): plastic pots covered with filter paper exposed to the substance in a closed chamber (volume: 74 L)
- Amount of soil: 100 g
- Method of seeding: seeds were given to the substrate (no further information concerning method of seeding)
- No. of seeds per container: 5
- No. of plants (retained after thinning): no thinning
- No. of replicates per treatment group: 4
- No. of replicates per control: 4


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Soil taxonomic classification: LUFA soil according to OECD 208
- Organic carbon (%): 1.34 ± 0.14%
- Maximum water holding capacity (in % dry weigth): no data


GROWTH CONDITIONS
- Photoperiod: 16 light / 8 darkness
- Light source: mercury vapour lamp
- Light intensity and quality: 2000 - 4000 lux
Nominal and measured concentrations:
nominal: 0, 10 and 100 ppmv (mL/m³)
measured: the measured values for 100 ppmv were reduced by 4 - 21 % compared to the concentrations measured in the supply air. The concentrations at 10 ppmv remained constant in supply and exhaust air.
Reference substance (positive control):
no
Species:
Lepidum sativum
Duration:
14 d
Dose descriptor:
EC50
Effect conc.:
> 100 other: ppmv
Basis for effect:
growth
Species:
Lepidum sativum
Duration:
14 d
Dose descriptor:
other: EC20
Effect conc.:
100 other: ppmv
Basis for effect:
growth
Species:
Avena sativa
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
100 other: ppmv
Basis for effect:
growth
Remarks:
and emergence
Details on results:
Avena sativa:
no effects on plant growth were be observed. No morphological anomalies observed.

Lepidium sativum:
Assay1:
Plant growth was 20% reduced after exposure to 10 and 100 ppmv ethylchlorid . No morphological anomalies observed.
Assay 2:
Plant growth was 20% reduced at a concentration of 100 ppmv ethylchlorid. No morphological anomalies observed.

Nominal concentration
[mL/m3]

Fresh weight [mg] at test end

 

 

Avena sativa

Lepidum sativum
1sttest

Lepidum sativum
2ndtest

 

0

232

63

43

 

10

214

46

38

 

100

237

49

34

 

Description of key information

Key value for chemical safety assessment

Additional information

Chloroethane is a gaseous substance and thus will mainly distribute to the air if released to the environment. There is no intended release of the substance to soil during its lifecycle. An exposure of the terrestrial compartment is therefore not anticipated.

Due to its gaseous nature chloroethane is characterised by a high vapour pressureof 134200 Pa at 20 °C (62330 Pa at 0 °C) and subsequently by a high evaporation rate from water to air as indicated by aHenry's Law constant of 1124.70 Pa m³/mol calculated for the substance. If the substance is released to the waste water it will rapidly evaporate from the water phase in conventional sewage treatment plants during the primary treatment. The substance will not adsorp to suspended matter or activated sludge as indicated by the low log Pow (1.34) and the correlated log Koc value (<3) . An exposure of soil via sewage sludge application can be excluded.

One study investigating the effect of chloroethane to terrestrial plants is available. The test investigated the effect of the substance on emergence and growth of the plant species Avena sativa and Lepidum sativum. The plants were exposed to the gas at concentrations of 10 and 100 ppmv in a closed chamber. The test was terminated after 14 days. Avena sativa was not affected by the substance. Whereas the growth of Lepidum sativum was reduced by 20% compared to control. Thus, the EC50(14d) for both plant species is > 100 ppmv.