Triphenyl phosphite

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: According to guideline and GLP with deviation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

Instead of a centrifuged sludge a settled sludge was used.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Triphenyl phosphite

EC Number:

202-908-4

EC Name:

Triphenyl phosphite

Cas Number:

101-02-0

Molecular formula:

C18H15O3P

IUPAC Name:

triphenyl phosphite

Details on test material:

- Physical state: liquid
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Details on test solutions:

Vessels: 250 ml BOD flasks with gas inlet
Water: Dechlorinated drinking water
Temperature: 20 ± 2°C
Nutrient solution:
16 g Peptone
11 g Meat extract
3.0 g Urea
0.7 g NaCI
0.4 g CaCl2 x 2 H20
0.2 g MgSO4 x 7 H20
2.8 g K2HP04
were dissolved and the volume made up to one liter with dechlorinated drinking water.

Remarks : 6.4 ml of the nutrient solution, 74 ml water, 40 ml of the stock solutions and 80 ml of the sludge were mixed in 250 ml BOD flasks and aerated immediately.

Stock solution and test solutions
499.8 mg test substance were mixed with 500 ml water by polytron for 5 minutes and made up to 1000 ml with water. (stock solution 500 mg/l for testconcentration 100 mg/l)
320 ml of the stock solution 500 mg/l were mixed and made up to 1000 ml with water, (stock solution 160 mg/l for test concentration 32 mg/l).
100 ml of the stock solution 500 mg/l were mixed and made up to 1000 ml with water (stock solution 50 mg/l for test concentration 10 mg/l).
100 ml of stock solution 160 mg/l were mixed and made up to 1000 ml with water, (stock solution 16 mg / I for testconcentration 3.2 mg/l).
100 ml of stock solution 50 mg/l were mixed and made up to 1000 ml with water, (stock solution 5 mg/l for test concentration 1 mg/l).
The stock solutions were freshly prepared at the start of the test

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge collected from the sewage treatment plant of CH-4153 Reinach on 06/02/95. The pH after collection was 7.6. The selected sewage work is treating predominantly domestic sewage. The preparation w^as carried out according to the method described in the guideline. The sludge was separated from the aqueous layer by settling instead of centrifugation. The pH of the sludge before use was 8.0.

Study design

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

20+-2°C

pH:

8.2-8.4

Dissolved oxygen:

Oxygen consumption per hour in mg/liter with a ORION - Electrode Type 97- 08, ORION Microprocessor lonalizer 901 and plotted on a recorder.

Nominal and measured concentrations:

Test substance : 100.0, 32.0,10.0, 3.2 and 1.0 mg/l
Reference substance : 32.0,10.0 and 3.2 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

EC50(3h) = 11.8 mg/l