Registration Dossier

Ecotoxicological information

Toxicity to terrestrial arthropods

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to terrestrial arthropods: short-term
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment
Remarks:
Study conducted according to a non Guideline protocol; not GLP; no analytical monitoring; moisture level low; no information on test item equilibration with the soil.
Qualifier:
according to
Guideline:
other: Lokke and van Gestel 1998
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
other: OECD 207(Earthworm, Acute Toxicity Tests)
Deviations:
yes
Remarks:
see below
Principles of method if other than guideline:
The test reduced moisture content of soil respect to the OECD guideline, 15-20% rather than 20-30%, but the authors of the report thought that this would make no difference to the survival of organisms due to the short duration of the test.
GLP compliance:
not specified
Application method:
soil
Analytical monitoring:
no
Vehicle:
yes
Details on preparation and application of test substrate:
- Method of mixing into soil: sand spike. This involved adding an appropriate amount of compound to analar grade acetone to form a stock solution for the 1000 mg/kg dose. Aliquots of the stock solution were then diluted with acetone to prepare lower doses. Acetone solutions were added to silica sand in glass jars. Mixtures were mixed thoroughly with a stainless steel spatula. The acetone was left to evaporate in a fume cupboard, leaving the test item coated onto the sand. Appropriate amount of moist soil was added to each of the glass jars. The dosed or undosed sand was incorporated into the bulk of the soil using a paletted knife. Jars were then sealed with screw top lids containing aluminium foil inserts and tumbled overnight (ca. 16 h) on a rotary soil tumbler 50 rpm.

- Controls: One aliquot of sand was dosed with acetone only to serve as solvent control. A jar with an aliquot of sand only served as untreated control - both with the appropriate amount of moist soil added thereafter.

- Chemical name of vehicle: acetone

- Concentration of vehicle in test medium: acetone solutions was added between 1-7 ml to 5-35g of silica sand. The sand was left to evaporate the acetone completely before initial exposure, so that the concentration of vehicle would be negligible.

- Evaporation of vehicle before use: yes
Test organisms (species):
Folsomia candida
Animal group:
Collembola (soil-dwelling springtail)
Details on test organisms:
TEST ORGANISM

- Common name: springtail

- Source: Centre of Ecology and Hydrology, Monks Wood, Cambridgeshire, UK

- Age at test initiation (mean and range, SD): 10-12 days old

ACCLIMATION

- Acclimation period: not specified.

- Acclimation conditions (same as test or not): similar to test
Study type:
laboratory study
Limit test:
no
Total exposure duration:
7 d
Test temperature:
range: 17.7 to 20 deg C
pH (if soil or dung study):
5.4.
Photoperiod and lighting:
16/8 hour daylight/darkness regime
Details on test conditions:
TEST SYSTEM

- Test container (material, size): 120 ml clear glass powder jars, sealed with a screw top lid

- Amount of soil or substrate: 30 g wet weight soil

- No. of organisms per container (treatment): 10

- No. of replicates per treatment group: 3

- No. of replicates per control: 3

- No. of replicates per vehicle control: 3


SOURCE AND PROPERTIES OF SUBSTRATE

- Geographic location: Heath Farm, Leicester Lane, LandLook (Midlands), Leamington Spa, from Dr Graham Beard. OS map reference 32896926.

- Pesticide use history at the collection site: assumed to be pesticide free, as the field the soil was taken from land that had been set aside for 3-4 years.

- Collection procedures: the soil was sieved to 2 mm.

- Sampling depth (cm): 5-20cm to avoid surface root mat

- Soil texture

- % sand: 63.8%-64.8%

- Soil classification: sandy loam soil. The soil is described as soil series, Bomsgrove, standard soil number 33, variant.

- Organic carbon (%): 1.3%

- Maximum water holding capacity: ca. 40%

- Pretreatment of soil: the soil was treated with gamma radiation (27 KGy) in order to kill the indigenous nematodes and potential predators. However observation from extracted fresh soil indicated that interference from the indigenous population was likely to be insignificant. Consequently, the definitive test was carried out using unsterilised soil.

- Storage: stored in closed black plastic bags at 4 degC until required.


EFFECT PARAMETERS MEASURED: mortality (immobilisation) at the end of the test


VEHICLE CONTROL PERFORMED: yes


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 3

- Range finding study

- Test concentrations: 10, 100, 100 mg/kg

- Results used to determine the conditions for the definitive study: 7d EC50 100-100 mg/kg
Nominal and measured concentrations:
Nominal concentrations: 0, 300, 1000 mg/kg
Reference substance (positive control):
yes
Remarks:
dimethoate
Duration:
7 d
Dose descriptor:
EC50
Effect conc.:
530 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: immobility
Remarks on result:
other: (420-660)
Details on results:
- Mortality at end of exposure period: 100% at the highest concentration tested. See Table 1 for details.
Results with reference substance (positive control):
- Results with reference substance valid? yes

- Relevant effect levels: EC50 3.1 mg/kg

Table 1. Summary of findings.

 Dose (mg/kg dw soil)    Number of F. candida      % effect    
 live  dead/missing
Control         10  0  0
10   0  0
 10  0  0
 Acetone control        10  0 0
 9  1  10
10  0  0
 300        8  2  20
 7  3  30
 10  0  0
 1000        0  10  100
 2  8  80
 2  8  80
Validity criteria fulfilled:
yes
Conclusions:
A 7 d EC50 value of 530 mg/kg dw soil has been determined for the effects of tetradecanol on population numbers of the springtail F. candida.

Description of key information

No reliable, standard tests of terrestrial arthropods are available. Effects on F. candida: (7 d) EC50 530 mg/kg soil dw is available from a study of non assignable reliability. Long term: In accordance with Column 2 of REACH Annex X the study does not need to be conducted.

Key value for chemical safety assessment

Additional information

Short-term toxicity

A 7 d EC50 value of 530 mg/kg dw soil (1.3% organic carbon) has been determined for the effects of the test substance on population numbers of the Fulsomia candida (Shell, 2004).

This study reflects the only value that is available for this endpoint, though it is of non assignable reliability.

Long-term toxicity

In accordance with Column 2 of REACH Annex X, long-term toxicity testing with terrestrial invertebrates (required in Section 9.4.4) is not needed as the chemical safety assessment according to Annex I indicates that this is not necessary.

Moreover, considerable technical difficulties would be expected in the conduct of such a test, due to the very rapid biotic removal of the substance from the test system. Please refer to discussion of the long-term aquatic invertebrate and fish studies, and evidence of rapid removal in non-sterilised soils during method development for the adsorption/desorption study with natural soils in the environmental fate section.