Lithium potassium titanium oxide

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22/05/2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: EEC Directive 67/548 amended November 18, 1987 (87/302), Part C: Methods for the determination of ecotoxicity, Publication No. L133, "Biodegradation: Activated sludge respiration inhibition test", adopted May 30, 1988.

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Terraces L

IUPAC Name:

Terraces L

Constituent 2

Reference substance name:

Lithium Potassium Titanium Oxide

EC Number:

445-620-6

Cas Number:

39318-30-4

Molecular formula:

Hill Empirical formula: K(0.5-0.7) Li(0.27) Ti(1.73) O(3.8-3.95) CAS Empirical formula: K(0.5-0.7) Li(0.27) Ti(1.73) O(3.8-3.95)

IUPAC Name:

Lithium Potassium Titanium Oxide

Details on test material:

- Name of test material (as cited in study report): Terraces L
- Substance type: White powder
- Physical state: solid
- Analytical purity: 100 %
- Lot/batch No.: 2D79A
- Storage condition of test material: At room temperature in the dark

Sampling and analysis

Analytical monitoring:

not required

Test solutions

Vehicle:

no

Details on test solutions:

The synthetic sewage feed (16 ml) and an adequate amount of the test substance (49.6 mg) were mixed and made up to 300 ml with Milli-RO water. Activated sludge (200 ml) was added and the mixture was aerated in a 1 l bottle during the contact time, using a pipette as an aeration device. The flasks were filled up to 500 ml final volume. The final concentration was 100 mg/L. The test substance was tested in duplicate. Additionally, a control without test substance was included in duplicate. The reference substance was tested in triplicate.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

The sludge was coarsely sieved and washed with tap-water. After concentration a small amount of the sludge was weighed and dried at ca. 105°C to determine the amount of suspended solids (3.1 g/l of sludge, as used for the test). Before use the pH was checked (measured value: 7.6).
The batch of sludge was used on the subsequent day, therefore 50 ml of synthetic sewage feed was added to each litre of activated sludge at the end of the day. The sludge was kept aerated at test temperature until use.

Study design

Test type:

other: aerobic

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

0.5 h

Post exposure observation period:

the contents was poured into a 300 ml oxygen bottle, and the flask was sealed with an oxygen electrode connected to a recorder, forcing the air out of the vessel. Oxygen consumption was measured and recorded for approximately 10 minutes. During measurement, the sample was not aerated but continuously stirred on a magnetic stirrer. The pH was determined in the remaining part of the reaction mixture.

Test conditions

Test temperature:

20.2-20.5°C

pH:

8.0-8.1

Dissolved oxygen:

7.8-7.9 mg/L at the start of the test

Nominal and measured concentrations:

nominal 100 mg/L. No measured concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: All glass, 300 ml oxygen bottles and 1 l test bottles
- Aeration: continuous; clean, oil free air.
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Oxygen consumption was measured for approximately 10 minutes after the exposure period to determine the respiration rate.

Reference substance (positive control):

yes

Remarks:

3.5 dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

30 min

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: The EC50 of 3,5-dichlorophenol was in the accepted range of 5-30 mg/l (17.6 mg/l, regression line: Y = 58.04 X –22.24, Y = % inhibition and X = log concentration (mg/l)).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this present test, TERRACESS L was not toxic to waste water (activated sludge) bacteria at a concentration of 100 mg/l.

This concentration was prepared by direct addition of TERRACESS L to the test vessels and exceeded the solubility of TERRACESS L in water.