(ethyl 3-oxobutyrato-O1',O3)bis(propan-2-olato)aluminium

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:

22 July 2004 to 27 January 2005.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

451-250-6

EC Name:

-

Cas Number:

569318-35-0

Molecular formula:

C11 H19 Al O5

IUPAC Name:

Aluminium 1, 3-butanediol ethyl acetoacetate complexes

Test material form:

solid

Specific details on test material used for the study:

The substance is the Source of the read-across.
The test material hydrolyses quickly (t1/2 < 3 h). Based on advice from the UK Environment Agency, the test material was ground and stirred in diluent to allow hydrolysis, and expose test organisms to hydrolysis products.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Smaples were taken from the control and each test group at 0 and 72 h for quantitative analysis.

Test solutions

Vehicle:

no

Details on test solutions:

XP 338: The test material was known to rapidly hydrolyse releasing butane-1,3-diol and ethyl acetoacetate. These are water soluble, but the co-formed aluminium hydroxide is poorly soluble (1.5 mg/L at 20 °C), so the test material was filtered to remove solids that may have exerted a physical effect on the test organisms.

Test organisms

Test organisms (species):

Scenedesmus sp.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

24 °C

pH:

7.5

Nominal and measured concentrations:

Nominal test concentration were 1.0, 3.2, 10, 32, 100 and 320 mg/L, besed in terms ofparent test material.
For ethyl acetoacetate: after 72 h there was a marked decline in the measured concentration. Given that stability analyses indicated that the substance was stable in culture medium over 72 h, this decline was considered to be due to adsorption to algal cells.
For butane-1,3-diol: after 72, there was a slight decline in measured concentrations. Given that stability analyses indicated that the substance was stable in culture medium over 72 h, this decline was also considered to be due to adsorption to algal cells.

Details on test conditions:

Following a preliminary range-finding test, algae was exposed to an aqueous solution of the hydrolysed test substance for 72 h under constant illumination and shaking at 24 °C.
Samples of the algal populations were removed daily, and cell concentrations determined for each control and treatment group, using a Coulter Multisizer particle counter.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 320 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

biomass

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

EbC50 (72 h) 7.3 mg/L; ErC50 (0 - 72 h) >320 mg/L.