2,2,6,6-tetramethyl-4-substituted-piperidinyl-1-oxy

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31st Oct 2007 - 15th Nov 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed in accordance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD test guideline 209

GLP compliance:

yes

Test material

Test material information

Constituent 1

Test material form:

other: Liquid

Sampling and analysis

Analytical monitoring:

not required

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Collected on each day of the test from Cambridge Sewage Treatment Works, Cowley Road, Cambridge.

Study design

Test type:

other:

Total exposure duration:

3 h

Test conditions

Test temperature:

21 ± 2 °C

pH:

Not specified

Dissolved oxygen:

Monitored using an oxygen electrode - abiotic control (1000mg/) : 8.51 mg/L dissolved oxygen at T0.

Nominal and measured concentrations:

Nominal concentrations : 62.5, 125, 250, 500, 1000, 2000 mg/L

Reference substance (positive control):

yes

Remarks:

3, 5-Dichlorophenol (3,5-DCP)

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

593 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

- Results with reference substance valid? Yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The IC50 of Inhibitor AHM P500 to the respiration rate of activated sludge was estimated as 593 mg/L (95% confidence limits of 343 to1288 mg/L. The validity controls were considered acceptable.

Executive summary:

A GLP study was performed in accordance with OECD 209 in order to assess the effect of Inhibitor AHM P500 to the respiration rate of activated sludge.

Based on the results of the preliminary test, nominal concentrations of 62.5 – 2000mg/L were used in the test. The test was run at 21±2°C. The dissolved oxygen was determined using an oxygen meter for a period of 10 minutes after an incubation period of 3hours from inoculation. A positive control (3,5-DCP) was included in the test.

Based on the results, the IC50 of Inhibitor AHM P500 to the respiration rate of activated sludge was estimated to be 593 mg/L (95% confidence limits of 343 to1288 mg/L). The validity controls were considered acceptable.