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

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 January 2004 to 16 March 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Aluminium ethyl acetoacetate neopentyl glycol complexes

Cas Number:

569319-64-8

Molecular formula:

C11H19AlO5

IUPAC Name:

Aluminium ethyl acetoacetate neopentyl glycol complexes

Test material form:

solid: crystalline

Specific details on test material used for the study:

The substance is the Source of the read-across.

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

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 sterile diluent for 96 h at 21 °C to allow hydrolysis, and expose test organisms to hydrolysis products.
The organic hydrolysis products 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):

activated sludge of a predominantly domestic sewage

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms was obtained from the aeration stage of the Sever Trent Water PLC sewage treatment plant at Loughborough, Lecestershire, UK, which treats predominantly domestic sewage.
The activated sample was maintaine on continuous aeration at 21 °C and was used on the day of collection. pH 7.7.

Test conditions

Hardness:

100 mg CaCO3/L

Test temperature:

21 °C

pH:

7.7

Conductivity:

415.9 uS/cm.

Nominal and measured concentrations:

1000 mg/L (expressed in terms of parent test material)

Details on test conditions:

Activated sewage sludge was exposed to a saturated solution of teh hydrolyis products of the test material at a concentration of 1000 mg/L (expressed in terms of parent test material) (three replicate flasks_ for a period of 3 h at 21 °C with teh addition of a syntheic sewage as a repiratory substrate.
The rate of respiration was determined after 30 min and 3 h contact time and compared to data for the control and a reference material 3,5-dichlorophenol.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

inhibition of total respiration

Effect concentrations 2

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

The reference material gave a 3 h EC50 of 12 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

3 h EC50 >1000 mg/L; NOEC 1000 mg/L.