Chloroethane

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

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

Key result

Species:

Lepidum sativum

Duration:

17 d

Dose descriptor:

LOEC

Effect conc.:

264.1 other: mg/m^3

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Analytically confirmed (ca. 98% of nominal)

Basis for effect:

growth

Remarks on result:

other: Original concentration value given as 100 ppm_v

Key result

Species:

Lepidum sativum

Duration:

17 d

Dose descriptor:

NOEC

Effect conc.:

26.4 other: mg/m^3

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Analytically confirmed (ca. 112 % of nominal)

Basis for effect:

growth

Remarks on result:

other: Original concentration value given as 10 ppm_v

Species:

Avena sativa

Duration:

17 d

Dose descriptor:

NOEC

Effect conc.:

265.4 other: mg/m^3

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Analytically confirmed (ca. 98% of nominal)

Basis for effect:

growth

Remarks:

and emergence

Remarks on result:

other: Original concentration value given as 100 ppm_v

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/m^3]	Fresh weight [mg] at test end
(ppm_v)	Avena sativa (n; SD)	Lepidum sativum 1^sttest (n; SD)	Lepidum sativum 2^ndtest (n; SD)
0	232 (18; 61)	63 (17; 12)	43 (19; 10)
10	214 (17; 58)	46 (18; 12)	38 (18; 7)
100	237 (20; 57)	49 (17; 14)	34 (17; 6)

 

Avena Sativa (only experiment 1, 23 °C):			NOEC	100	ppm	equiv. To	265.4	mg/m^3
				10 ppm	100 ppm	10 ppm equiv. To	100 ppm equiv. To
Lepidium Sativum Experiment 1 (23 °C):			Effect [%]	24*	22.2*	26.54	265.4	mg/m^3
Lepidium Sativum Experiment 2 (26 °C):			Effect [%]	11.6	20.9*	26.27	262.7	mg/m^3
		Arithmetic mean Exp. 1/2				26.4	264.1	mg/m^3
		*) statistically significant		NOEC / EC10	LOEC	NOEC / EC10	LOEC
Analytical verification within +/- 20% of nominal ==> evaluation based on nominal concentration

 

 

Validity criteria fulfilled:

yes

Conclusions:

By conversion of ppmv to mg/m^3 via molecular weight, atmospheric pressure and the temperature measured during the test, the following key results were derived:

NOEC (17 d; growth; Lepidium sativum) = 26.4 mg/m^3
LOEC (17 d; growth; Lepidium sativum) = 264.1 mg/m^3

Executive summary:

The study investigated the effect of the gas chloroethane towards terrestrial plants due to exposure via the gas phase. The study was performed according to OECD 208 (Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test) modified for atmospheric exposure. The effect of chloroethane on the emergence and growth of the plant species Avena sativa and Lepidium sativum were investigated. The plants were exposed to the gas at concentrations of 10 and 100 ppmv in a closed chamber. Nominal test concentrations were analytically verified and confirmed. The test was terminated after 17 days. Avena sativa was not affected by the substance, whereas the growth of Lepidium sativum was reduced by 20% at the highest concentration of 100 ppmv (statistically significant; LOEC).

By conversion of ppmv to mg/m^3 via molecular weight, atmospheric pressure and the temperature measured during the test, the following key results  were derived:

NOEC (17 d; growth; Lepidium sativum) = 26.4 mg/m^3

LOEC (17 d; growth; Lepidium sativum) = 264.1 mg/m^3

Reference 2

Endpoint:

toxicity to terrestrial plants: long-term

Data waiving:

exposure considerations

Justification for data waiving:

the study does not need to be conducted because direct and indirect exposure of the soil compartment is unlikely

other:

Description of key information

Exposure of the below ground soil compartment as defined by REACH for terrestrial toxicity is not relevant for the gas chloroethane (waiving).

A relevant supporting study for above ground atmospheric exposure of plants is available, and the NOEC of 26.4 mg/m^3 (key value) is used as the basis for PNEC_air. The value cannot be specified below as key value because no units for mass/volume concentrations are foreseen.

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 and risk assessment based on EPM indicates no risks for the soil compartment (see waiving for details).

A relevant supporting study investigating the effect of chloroethane to terrestrial plants is available. The study was performed according to OECD 208 (Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test) modified for atmospheric exposure.  The effect of chloroethane on the emergence and growth of the plant species Avena sativa and Lepidium sativum were investigated. The plants were exposed to the gas at concentrations of 10 and 100 ppmv in a closed chamber. Nominal test concentrations were analytically verified and confirmed. The test was terminated after 17 days. Avena sativa was not affected by the substance,  whereas the growth of Lepidium sativum was reduced by 20% at the highest concentration of 100 ppmv (statistically significant; LOEC).

By conversion of ppmv to mg/m^3 via molecular weight, atmospheric pressure and the temperature measured during the test, the following key values were derived:

NOEC (17 d; growth; Lepidium sativum) = 26.4 mg/m^3

LOEC (17 d; growth; Lepidium sativum) = 264.1 mg/m^3

 

The NOEC is used to derive a PNEC_air for chloroethane.