Reaction product of ammonium molybdate and C12-C24-diethoxylated alkylamine (1:5-1:3)

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 September 2007 to 12 September 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.6800 (Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction product of ammonium molybdate and C12-C24-diethoxylated alkylamine (1:5-1:3)

EC Number:

412-780-3

EC Name:

Reaction product of ammonium molybdate and C12-C24-diethoxylated alkylamine (1:5-1:3)

Cas Number:

1380226-46-9

Molecular formula:

A complex mixture of species so no unique molecular formula can be given

IUPAC Name:

dimolybdenum(6+) diammonium 2-{2-[(octadec-9-en-1-yl)amino]ethoxy}ethan-1-ol heptaoxidandiide

Test material form:

liquid: viscous

Details on test material:

- Name of test material: Additiv 104
- Description: dark amber coloured liquid
- Batch number: 651069622
- Date received: 23 August 2007
- Storage conditions: room tempertaure in the dark

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No data reported

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

For the purpose of the definitive test, the test material was dispersed directly in water.

An amount of test material (500mg) was dispersed, via plastic disposable syringe, in approximately 250ml of water and subjected to ultrasonication for approximately 15 minutes. Synthetic sewage (16 ml), activated sludge (200 ml) and water were added to a final volume of 500 ml to give the required concentration of 1000 mg/l.

This method of preparation was performed for the three seperate test vessels.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

The activated sewage sludge sample was maintained on continuous aeration in the laboratory at a temperature of approximately 21 °C and was used on the day of collection. The pH of the sample was measured using a WTW pH/Oxi 3401 pH and dissolved oxygen meter. Determination of the suspended solids level of the activated sewage sludge was carried out by filtering a sample (100 ml) of the activated sewage sludge by suction through a pre-weighed GF/A filter paper using a Buchner funnel which was then rinsed 3 times with 10 ml of deionised reverse osmosis water
and filtration continued for 3 minutes. The filter paper was then dried in an oven atapproximately 105°C for at least 1 hour and allowed to cool before weighing. This process was repeated until a constant weight was attained. The suspended solids concentration was equal to 3.7 g/1 prior to use

Study design

Test type:

other: aerobic

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

Observations were made on the test preparations throughout the test period, and the pH of the control, reference material and test material preparations were measured using a WTW pH/Oxi 340I pH and dissolved oxygen meter at 0 hours and prior to measurement of the oxygen
consumption rate after 3 hours contact time.

Test conditions

Hardness:

The test water used for both the range-finding and definitive tests was laboratory tap water dechlorinated by passage through an activated carbon filter (Purite Series 500) and partly softened (Elga Nimbus 1248D Duplex water softener) giving water with a total hardness of approximately 140 mg/L as CaC03.

Test temperature:

21±1 °C

pH:

pH Values of the test preparations at the start and end of the exposure period (3 hours) ranged from 7.9 to 8.5

Dissolved oxygen:

No data reported

Salinity:

Not applicable

Nominal and measured concentrations:

In the range-finding test activated sewage sludge micro-organisms were exposed to a series of nominal test concentrations of 100 and 1000 mg. The test material was dispersed directly in water.
Based on the results of the range-finding test a "limit test" was conducted at a concentration of 1000 mg/l (three replicate vessels) to confirm that at this concentration no effect on respiration of the activated sewage sludge was observed

Details on test conditions:

At time "0" 16 ml of synthetic sewage was diluted to 300 ml with water and 200 ml of inoculum added in a 500 ml conical flask (first control). The mixture was aerated with clean, oil-free compressed air via narrow bore glass tubes at a rate of approximately 0.5 - 1 litre per minute.
Thereafter, at 15 minute intervals the procedure was repeated with appropriate amounts of the reference material being added. The test material vessels were prepared as described previously. Finally a second control was prepared. As each vessel reached 30 minutes contact time an aliquot was removed from the conical flask and poured into the measuring vessel (250 ml darkened glass Biological Oxygen Demand (BOD) bottle) and the rate of respiration measured using a Yellow Springs dissolved oxygen meter fitted with a BOD probe. The contents of the measuring vessel were stirred constantly by magnetic stirrer. The rate of respiration for each flask was measured over the linear portion of the oxygen consumption trace (where possible between approximately 6.5 mg O2/l and 2.5 mg O2/l). In the case of a rapid oxygen consumption, measurements may have been outside this range but the oxygen consumption was always within the linear portion of the respiration curve. In the case of low oxygen consumption, the rate was determined over an approximate 10 minute period. After measurement the contents of the BOD bottle were returned to the test vessel.

This procedure was repeated after 3 hours contact time. The test was conducted under normal laboratory lighting in a temperature controlled room at 21±1 °C.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol (Sigma-Aldrich Batch No. 15809KI-346)

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Details on results:

The effect of the test material on the respiration of activated sewage sludge gave a 3-Hour EC50 of greater than 1000 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/l. It was considered unnecessary and unrealistic to test at concentrations in excess of 1000 mg/l.

Results with reference substance (positive control):

The reference material gave a 3-Hour EC50 value of 7.0 mg/l, 95% confidence limits 5.3- 9.3 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test material on the respiration of activated sewage sludge micro-organisms gave a 3-Hour EC50 of greater than 1000 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/l.

It was considered unnecessary and unrealistic to test at concentrations in excess of 1000mg/l.

The reference material gave a 3-Hour EC50 value of 7.0mg'l, 95% confidence limits 5.3 - 9.3mg/l

Executive summary:

In a GLP compliant guideline Activated Sludge, Respiration Inhibition Test the effect of the test material on the respiration of activated sewage sludge micro-organisms gave a 3-Hour EC50 of greater than 1000 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/l.