Aluminium oxide

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Aluminiumchlorid wasserfrei gemahlen (PBG 10000464)
Test substance N°: 00/0813-2
Batch n°: 32254175L0
Homogenous; expery date october 2008
Chloride: 79.9 g/100 g, Aluminium: 20.0 g/100 g Total:99.9 g/100 g (BASF report No. 07L00322)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was weighed in the required amounts for the test concentrations directly to the test vessels. Than 180 mL demineralized water were added. The mixtures were stirred for 20 ± 2 hours at room temperature.
Aliquot of 50 mL of this suspension were added to the test vessels to obtain a sludge concentration of 1.5 g/L dry substance.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from the municipal wastewater treatment plant of Mannheim/Baden Württemberg, Germany was collected on 14 May 2008 from the aeration tank of the plant. The activated sludge suspension was washed 3 times with tap water and sieved with a fine woven mesh (mesh size about 1 mm). This suspension was adjusted to a concentration of 7.5 g/L dry weight and pre-aerated over night. After the pre-aeration the lost water of the suspension was replaced.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

Duration of the measurement of oxygen consumption: 8-10 minutes

Test temperature:

22 +/_ 2 °C

pH:

7.2 - 7.3 (corrected before addition of inocumum; pH before correction was situated between 3.3 and 5.6)
pH-values after incubation time: 7.8 - 8.1

Dissolved oxygen:

oxygen concentration during aeration:> 2.5 mg/L
oxygen concentration immediately before measurement: > 6.5 mg/L

Nominal and measured concentrations:

Nominal: 62,4, 125, 250, 500, 1000 mg/L test substance

Details on test conditions:

Test vessesls: Erlenmeyer vessels (nominal value 250 mL)
Test volume: 250 mL
Synthetic medium: 8 mL/vessel 100-fold concentrated OECD medium

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

> 200 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

EC50 of 3,5 dichlorophenol is in the range of 5-30 mg/L (validity criteria has been met)

Assay identification	Blanc#1	Blanc#2	1000 mg/L	500 mg/L	250 mg/L	125 mg/L	62.5 mg/L
O2 conc at start (mg/L)	8.0	7.6	7.5	8.1	8.1	8.1	7.7
O2 conc. after 6 min (mg/L)	6.5	6.0	6.0	6.5	6.5	6.5	6.0
O2 consumption rate (mg/L in 6 min)	1.5	1.6	1.5	1.6	1.6	1.6	1.7
O2 consumption rate (mg/L x h)	15	16	15	16	16	16	17
Specific O2 consumption rate (mg/g x h)	10	11	10	11	11	11	11
Calculation of inhibition respiration (%)	--	--	3	-3	-3	-3	-10

Validity criteria fulfilled:

yes

Conclusions:

In conclusion the 180 minutes EC10 and EC20 values for Aluminiumchlorid wasserfrei gemahlen (PBG 10000464) in the Activated Sludge Respiration Inhibition Test was >1000 mg/L. The EC50 was >1000 mg/L.
No signification inhibition was noted in any of the tested concentration levels.

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

Summary of available data used for the endpoint assessment of the target substance

Adequacy of study:

key study

Justification for type of information:

Refer to analogue justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

> 200 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of total respiration

Description of key information

One activated sludge respiration inhibition test is available with a soluble aluminium salt. This test was performed with aluminum chloride according to standard guideline. No effects were seen up to the highest test concentration of 1000 mg/L test material. The test substance contained 20 g Al/100 g and the test concentrations can be converted to mg/L Al. 1000 mg/l test material is equal to 200 mg/l Al.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

200 mg/L