Isooctadecan-1-ol

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: short-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: Study conducted according to a modified OECD guideline, no mention of GLP and no analytical monitoring.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Donkin & Dusenberry (1993)

Deviations:

yes

Remarks:

method of test animals recovery from vials changes, lower soil moisture.

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

yes

Remarks:

as above

Principles of method if other than guideline:

The test method was modified to improve the recovery rate of test animals. The amount of soil requiring extraction was reduced, worms were extracted by adding 5ml Ludox HS40 to each vial then shaking the vial vigorously on a 'whirlmixer'. The Ludox/soil suspension were centrifuged for longer and at a higher speed (7000 rpm and for 15 minutes) in order to improve the clarity of the supernatant, which was sieved and the organisms rinsed with M9 salt solution and counted under a high power microscope. The test also 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

Test material

Test material information

Constituent 1

Reference substance name:

Tetradecanol

EC Number:

204-000-3

EC Name:

Tetradecanol

Cas Number:

112-72-1

IUPAC Name:

112-72-1

Constituent 2

Reference substance name:

tetradecanol

IUPAC Name:

tetradecanol

Details on test material:

- Name of test material (as cited in study report): tetradecanol - C14

- Physical state: white, semi-solid

Sampling and analysis

Analytical monitoring:

no

Test substrate

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil: sand spike, using 10% of the total dry weight of soil. 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 500 ml amber 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

Test organisms (species):

Caenorhabditis elegans

Animal group:

nematods

Details on test organisms:

TEST ORGANISM

- Common name: nematode

- Source: Sanger Centre, Wellcome Trust Genome Campus, Hinxton, Cambridge.

- Age at test initiation (mean and range, SD): adult nematodes, 2 days old.


ACCLIMATION

- Acclimation period: none, organisms were removed from mixed age populations and juveniles allowed to mature within 2 days.

Study design

Study type:

laboratory study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

none

Test conditions

Test temperature:

20 +/- 2 degC

pH:

5.4-5.5

Moisture:

18% +/- 1%

Details on test conditions:

TEST SYSTEM

- Test container (material, size): 50 ml clear glass vials

- Amount of soil or substrate: 10 g wet weight of sterilised 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

The test was preformed with other species, all details of the test were similar, except for the exposure system in which the test were carried was different. See Table 2 for details.


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 were carried out using unsterilised soil.

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


OTHER TEST CONDITIONS

- Photoperiod: vials were placed in the dark.


EFFECT PARAMETERS MEASURED: mortality (immobilisation) at the end of the test, i.e. after 72 h


VEHICLE CONTROL PERFORMED: yes


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 3

- Range finding study: not conducted

Nominal and measured concentrations:

Nominal concentrations: 0, 10, 30, 100, 300, 1000 mg/kg

Reference substance (positive control):

yes

Remarks:

dimethoate

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction and survival

Details on results:

- Mortality at end of exposure period: at the end of the exposure (72 h) mortality at the highest conc. (300 mg/kg dw) was 100%. See table 1 for details. Mortality is actually immobility, measured through response to touch and missing individuals.

See table 2 for details on results with other species.

Results with reference substance (positive control):

- Results with reference substance valid? no since there was no mortality observed. Organisms thought to be tolerant by the authors of the report.

Reported statistics and error estimates:

Probit analysis (Finney 1971) was used to determine EC50 values and their corresponding 95% intervals in definitive tests.

Any other information on results incl. tables

Table 1. Result of C. elegans exposure to decanol, number of surviving animals and offspring combined at 72 h.

Compound	Dose (mg/kg dw soil)	Number ofC. elegans found in extracts (average)
Control	-	36
Solvent control	-	40
Dimethoate	100	33
	300	23
	1000	23
C14
	100	46
	300	49
	1000	73

Solvent control is acetone used (up to 7 ml of acetone was used to prepare stock solutions with sand, then added to soil, however the acetone was left to evaporate before exposure).

The EC value should be normalised to a soil with 2% organic matter according to the following equation.

 

NOEC or L(E)C50 (standard) = NOEC or L(E)C50 (exp) * [ Fom soil(standard)/ Fomsoil(exp)]

 

Where Fom soil = fraction organic matter in soil

 

So72h EC50 >1000 mg/kg dw * [2%/1.3%] = >1000 * 1.5 = 1500 mg/kg dw

Table 2. Results of the test conducted with species: Eisena futida, Fulsomia candida, Heterocypris incongruens.

Species	Duration (d)	EC50 (mg/kg dw)
Eisena fetida	7	>1000
Heterocypris incongruens	6	>1000
Fulsomia Candida	7	530

Results are based on reproduction and survival.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A 72 h EC50 value of >1000 mg/kg dw soil has been determined for the effects of the test substance on population numbers of the nematode C. elegans.