Phosphoric acid, bis(phenylmethyl) ester, potassium salt (1:1)

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

1996-01-21

Test material

Test material information

Constituent 1

Reference substance name:

potassium dibenzyl phosphate

EC Number:

616-628-9

Cas Number:

78543-37-0

Molecular formula:

C14-H14-O4-P.K

IUPAC Name:

potassium dibenzyl phosphate

Test material form:

solid

Details on test material:

Batch 97/8

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Amixed population of activated sewage sludge micro-organims was obtained on 19 may 1997 from the aeration stage of the SevernTrent Plc sewage treatment plant at Belper, Derbyshire, UK, which treat predominatly domectis sewage

- Preparation of inoculum for exposure: the sample of activared sludge was maintained on continuous aeration upon receipt. A sample of the activated sludge was washed three times by settlement and resuspension in culture medium to remove an excessive amounts of Dissolved Organic Carbon (DOC) that may have been present. A sub-sample of the washed sewage sludge was then removed and the suspended solids concentration determined.
- Pretreatment:
- Concentration of sludge: 30 mg suspended solid (ss/L)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

56

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

99% degradation after 28 days. The results are corrects.

Any other information on results incl. tables

Percentage biodegration value

Day	% degradation Sodium Benzoate	% degradation ITC 780	% degradation ITC 780 plus sodium Benzoate Toxicity control
0	0	0	0
1	6	1	0
2	24	3	10
3	57	8	26
6	60	21	21
8	76	29	32
10	80	37	44
14	81	40	55
16	87	44	72
20	90	48	76
22	91	50	80
24	98	53	86
27	99	54	86
28	99	56	88
29*	100	61	89

* Day 29 values corrected to included any carry-over of Co2 detected in absorber 2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The Dibenzyl Potassium Phosphate was not considered to be readely bioegradable

Executive summary:

The readely biodegradability of Dibenzyl Potassium Phosphate has been determined according to OECD 301B test guideline in compliance with GLP.

The substance was determined to be not readely biodegradable.