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

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09.12.2008 - 12.12.2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

Method C.3

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

249-636-2

EC Name:

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

Cas Number:

29450-45-1

Molecular formula:

C17H25ClO3

IUPAC Name:

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

impurity 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

Test material form:

liquid

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 0.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

< 0.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

> 32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

other: EyC50

Effect conc.:

13.04 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Any other information on results incl. tables

RESULTS AND DISCUSSION

The following results were obtained in the study:

·        increase of biomass in control during 72 h was 253 times (criterion – not less than 16 times)

·        coefficient of variation for specific growth rate for control in the whole period of test (_t0-t₇₂) is: 1.1 % (criterion – not more than 7%),

·        the mean coefficient of variation for section-by-section specific growth rates in the control cultures was 34.7% (criterion – not more than 35%)

Applicant's summary and conclusion

Executive summary:

Growth inhibition assessment was performed according to the OECD Guideline No 201, method C.3, as well as in compliance with Principles of Good Laboratory Practice (GLP, OECD 1997).

 

The aim of the study was determination of growth inhibition of algae Pseudokirchneriella subcapitata exposed to the range of concentrations (expressed as the ErCx in mg/l after 24, 48 and 72 h exposure) and also determination of yield inhibition (expressed as the EyCx in mg/l after 24, 48 and 72 h exposure) as well as the values LOEC and NOEC.

 

Test material was used in 5 concentrations in range from 0.32 mg/L to 32.0 mg/L.

Mean concentration causing 50% inhibition of yield inhibition of Pseudokirchneriella subcapitata culture (EyC50/72 h) is 13.04 mg/L, and mean concentration causing 50% of average specific growth rate (ErC50/72 h) is above 32.0 mg/L (based on nominal concentrations of the test item).

 

The LOEC and NOEC values are below 0.32 mg/L for yield and for average specific growth rate (based on nominal concentrations of the test item).