α,α-diphenylpiperidine-4-methanol hydrochloride

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Test start: November 28 1997 - End of the experimental part of the test: January 15 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD, GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

Abridged version

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Azacyclonol

EC Number:

204-092-5

EC Name:

Azacyclonol

Cas Number:

115-46-8

IUPAC Name:

diphenyl(piperidin-4-yl)methanol

Test material form:

solid - liquid: suspension

Details on test material:

- Name of test material (as cited in study report): Azacyclonol-Base (Lepetit)
- Analytical purity: 98.3% (w/w)
- Lot/batch No.: 960050
- Analysis Certificate No.: 523928957/30795 dated 01.04.1997
- Expiration date of the lot/batch: 10-09-1998

Test organisms

Test organisms (species):

activated sludge of a predominantly industrial sewage

Details on inoculum:

- Origin: waste water treatment plant in the city of Frankfurt am Main in Sindlingen
- Type of inoculum: washed activated sludge of a municipal wastewater treatment plant
- Preparation of the suspension: activated sludge sediment was centrifuged three times and then resuspended in water with 0.9% NaCl.
- Quantity of inoculum: 450 mL/L sludge suspension
- Sludge content: 21.8 g/L (centrifuged sludge sediment)
- Solids: 3.56 g/L (dry matter)
- Content in the final volume testing: 1.6 g/L (dry matter)

Study design

Test type:

not specified

Water media type:

not specified

Total exposure duration:

3 h

Test conditions

Test temperature:

Audit temperature: 18.6°C to 20.3°C

pH:

Audit pH: 8.4 to 8.9 after incubation

Nominal and measured concentrations:

Highest concentration of test material: 1000 mg/L
Lowest concentration of test material: 31.3 mg/L
Spacing factor for test concentrations: ca. 2 (factor between concentration values​​)

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol (3,5-DCP)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

ca. 56 mg/L

Nominal / measured:

meas. (arithm. mean)

Remarks on result:

other: 18 mg/L to 97 mg/L

Effect concentrations 2

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

ca. 206 mg/L

Nominal / measured:

meas. (arithm. mean)

Remarks on result:

other: 124 mg/L to 358 mg/L

Effect concentrations 3

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

ca. 759 mg/L

Nominal / measured:

meas. (arithm. mean)

Remarks on result:

other: 421 mg/L to 2633 mg/L

Results with reference substance (positive control):

The EC50 of the reference substance 3,5-dichlorophenol following value was obtained: 16 mg/L (95 % CL: 10 to 25 mg/L).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 of Azacyclonol base compared to activated sludge (waste water treatment plant) is in the range> 100 to 1000 mg/L.
Given that Azacyclonol base will decrease the acidity as observed in short term toxicity on fish (cf 6.1.1), the ecotoxicity profile of free base could beused as reference.