2-ethylhexyl (4-chloro-2-methylphenoxy)acetate

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19.05.2004 - 02.06.2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

read-across source

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(4-chloro-2-methylphenoxy)acetic acid

EC Number:

202-360-6

EC Name:

(4-chloro-2-methylphenoxy)acetic acid

Cas Number:

94-74-6

Molecular formula:

C9H9ClO3

IUPAC Name:

(4-chloro-2-methylphenoxy)acetic acid

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

impurity 2

Reference substance name:

4-chloro-o-cresol

EC Number:

216-381-3

EC Name:

4-chloro-o-cresol

Cas Number:

1570-64-5

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-2-methylphenol

Test material form:

solid

Results and discussion

Effect concentrations

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil ww

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Any other information on results incl. tables

RESULTS

Taking into account the obtained results it was assessed that MCPA TECH-NICAL did not cause mortality of earthworms and changes in behavior and appearance of earthworms, in relation to the control, were not observed. After 14 days of the test, decrease of the earthworms weight in all concentrations was observed, because earthworms was not fed during the experiment. Decrease of earthworms weight in relation to the control was not observed. In concentrations 62.5 — 500 mg/kg dry weight of artificial soil, decrease of earthworms weight was smaller than in control but in the highest concentration decrease of earthworms weight was on the same level as in control.

It was found that:

·        median lethal concentration causing 50% of mortality of earthworms population (LC50) after 7 and 14 days is above 1000 mg/kg of dry artificial soil,

Applicant's summary and conclusion

Executive summary:

The methodical basis of the study was OECD Guidelines No 207 and Good Laboratory Practice (GLP).

The scope of the study was to assess the acute toxicity to earthworms and determine the LC₅₀, LC₀and LC₁₀₀values.

The test species was Eisenia fetida, Say. The tested substance in a form of water suspension was introduced into soil in concentrations of 62.5; 125, 250, 500 and 1000 mg/kg (artificial soil dry weight). The test duration was 14 days. The animals were weighed following this time and alive animals were counted.

Taking into account the obtained results it was assessed that MCPA TECHNICAL did not cause mortality of earthworms and changes in behavior and appearance of earthworms in relation to the control were not observed.

After 14 days of the test, decrease of earthworms weight in relation to the control was not observed. In concentrations: 62,5 — 500 mg dry weight of artificial soil decrease of earthworms weight was smaller than in control but in the highest concentration decrease was on the similar level as in control.

Concentration causing 50% mortality of earthworms population (LC₅₀) after 7 and 14 days is above 1000 mg/kg of dry soil.