Retinol

Toxicity to microorganisms

Administrative data

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:

other: GLP-guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

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:

Retinol

EC Number:

200-683-7

EC Name:

Retinol

Cas Number:

68-26-8

Molecular formula:

C20H30O

IUPAC Name:

(2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-en-1-yl)nona-2,4,6,8-tetraen-1-ol

Details on test material:

- Name of test material (as cited in study report): Retinol crystalline
- Lot/batch No.: 090-04-06
- Analytical purity: 93.9 %

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge from laboratory wastewater plant treating municipal sewage. Concentration of the dry substance 1 g/l.
Preparation of the inoculum : The inoculum was washed and brought to a concentration of 5 g/I dry substance, then aerated during the night (24 h). 50 ml was added to the test solution total volume of 250 ml to obtain a concentration of 1 g dry substance/l in the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

180 min

Test conditions

Test temperature:

20 +/- 2 °C

Dissolved oxygen:

Oxygen concentration during aeration: > 2.5 mg/l
Oxygen concentration immediately before measurement: > 6.5 mg/l
Duration of the measurement of oxygen consumption: 8-10 min

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer-vessel (nominal volume 250 ml)
- Fill volume: 250 ml


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic medium: 8 ml/vessel 100-fold concentrated OECD medium

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenole

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

180 min

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

180 min

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

180 min

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

Reference substance: EC50 = 27 mg/l