Reaction product of phosphorus trichloride with reaction mass of 4-tert-butylphenol and phenol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: according to guideline and GLP, no deviations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,4-di-tert-butylphenyl diphenyl phosphite; 2-tert-butylphenyl diphenyl phosphite; 4-tert-butylphenyl diphenyl phosphite; triphenyl phosphite

EC Number:

941-802-9

Molecular formula:

Unspecified

IUPAC Name:

2,4-di-tert-butylphenyl diphenyl phosphite; 2-tert-butylphenyl diphenyl phosphite; 4-tert-butylphenyl diphenyl phosphite; triphenyl phosphite

Test material form:

other: yellowish liquid

Details on test material:

purity 100%

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

21 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

21.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium:
according to guideline
Stock solutions:
a)
KH2PO4 8.5g/L
K2HPO4 21.75 g/L
Na2HPO4 x 2H2O 33.4g/L
NH4Cl 0.5g/L
b)
MgSO4 x 7H2O 22.5g/L
c)
CaCl2 x 2H2O 36.4 g/L
d)
FeCl3 x 6H2O 0.25g/L + 1 drop concentrated HCl
Final test water (1000mL): 10mL solution a) + 1mL each of solution b)-d) + purified water
pH adjsuted to 7.4 with diluted hydrochloric acid solution


- Test temperature: 23-24°C
- pH: 7.4 day 0 after addtion of test item/refrence item
- Aeration: CO2 free air
- Suspended solids concentration: 30mg dry material per liter
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 54-liter allglass amber bottles
- Number of culture flasks/concentration: 9 flasks: 2 test item, 2 for reference item, 2 for inoculum control, 1 abiotic control, 1 abiotic control blank, 1 toxicity control
- Method used to create aerobic conditions: 30-100mL/min CO2 free air

SAMPLING
- Sampling frequency: Day 2, 5 9, 12, 14, 19, 23, 28, 29
- Sampling method: inorganic carbon analysis of aliquot 2mL from absorber flask (Shimadzu TOC-500 Analyser)
- Other: on Day 28 1mL concentrated HCl was added to each test flask for measurement of residual CO2 on day 29

CONTROL AND BLANK SYSTEM

- Abiotic control/abiotic control blank: 10mg/L mercury dichloride
- Toxicity control: 21.3 mg/L test item + 25.7 mg/L reference itemsodium benzoate

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

41.6

Sampling time:

28 d

Details on results:

Biodegradation after 14 days: 34.5 - 25.6 %
Biodegradation after 28 days: 36.5 - 46.6%


The test item had no inhibitory effect on activated sludge microorganisms because the biodegradation rate in the toxicity control was >25%
within 14 days.

BOD5 / COD results

Results with reference substance:

In the procedure controls, the reference item was degraded by an average of 79.0% by bexposure Day 14, thus confirming suitability of the activated sludge. At the end of the test (Day 28), the reference item was degraded by an average of 80.6%.
The biodegradation rate in the toxicity control showed a similar course over the 28-day exposure period as the two procedure controls containing the reference item, only. Within 14 days of exposure, a biodegradation rate of 70.4% was observed.

Any other information on results incl. tables

Maximum 1.85 mg C/L was found in the absorber flasks on day 29. Consequently, only negligible amounts of residual CO2 were present in the test solutions at the end of the test.