Phenyl diamidophosphate

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:

2013-01-30 - 2013-04-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an internationally accepted guideline. All study parameters are based on the specific guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

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:

Phenyl diamidophosphate

EC Number:

231-218-6

EC Name:

Phenyl diamidophosphate

Cas Number:

7450-69-3

Molecular formula:

C6H9N2O2P

IUPAC Name:

[(diaminophosphoryl)oxy]benzene

Test material form:

solid: crystalline

Details on test material:

Name PPDA
Composition phosphoric acid phenylester diamide, contains 4.9% ammonium chloride and 2.9% phenol
CAS No. 7450-69-3
EINECS-No. 231-218-6
Molecular formula C6H9N2O2P
Molecular weight 172.1 g/mol
Purity 92.2% (HPLC)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Specification
Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.

Source
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf.

Pre-Treatment
The sludge was filtrated, washed with tap water twice, then washed with and re-sus-pended in test medium. It was then aerated for  12 hours. The dry matter was determined with 3700 mg suspended solids/litre.

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

Details on study design:

The medium was prepared from the stock solutions. The stock solution of the positive control was prepared and its TOC was measured. The stock solution of the test item was prepared and its TOC was measured. The inoculum was taken from its source, washed, aerated and the dry matter was determined.
The test vessels were filled with medium and inoculum. Then all flasks were aerated for 72 hours with purified, CO2-free, moistened air to purge the system of CO2.
The test vessels were aerated with purified (by activated charcoal), CO2-scrubbed, mois-tened air. The scrubbing of carbon dioxide was achieved by bubbling the purified air through a flask containing 1.5 m-NaOH. To control the absence of CO2, the air was then led through a flask containing a solution of Ba(OH)2 before reaching the test vessels.
Magnetic stirrers were used to prevent deposition of inoculum.
The emitted CO2 was trapped in 0.25-m-NaOH. Two scrubbers containing 100 mL each were connected in series to the test vessels. The initial IC value of the 0.25 m-NaOH was separately determined in each flask.
Sampling
From each front scrubber flask, ten samples were taken in order to determine the emitted CO2 (on days 0, 2, 4, 7, 9, 11, 14, 18, 23 and 29). The sample volume was 1 mL. The re-sulting change in the volume of the front flask was considered in the calculation of emitted CO2.
On day 28, 5 mL HCl 2-m. were added to each test flask in order to drive off dissolved CO2. On day 29, samples from both scrubber flasks were taken.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

2.1

Sampling time:

2 d

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

14.3

Sampling time:

7 d

% Degradation 3

Parameter:

% degradation (CO2 evolution)

Value:

59.8

Sampling time:

11 d

% Degradation 4

Parameter:

% degradation (CO2 evolution)

Value:

72.6

Sampling time:

18 d

% Degradation 5

Parameter:

% degradation (CO2 evolution)

Value:

76.7

Sampling time:

29 d

Any other information on results incl. tables

Emitted carbon in mg/L

Day	Control 1	Control 2	Positive Control 1	Positive Control 2	Test 1	Test 2	Abiotic Control	Toxicity Control
2	0.59	0.42	0.53	0.48	1.00	0.88	0.12	0.33
4	1.41	1.01	4.91	1.60	2.00	1.84	0.24	2.79
7	1.92	1.95	12.32	10.55	4.46	5.16	0.18	13.13
9	2.13	2.32	15.87	13.52	10.49	8.36	0.05	16.54
11	2.36	2.63	18.31	16.10	15.03	14.00	-0.01	19.76
14	2.77	2.86	19.61	17.69	16.74	17.07	-0.03	23.38
18	2.77	2.97	19.68	18.76	17.27	17.68	-0.03	25.86
23	2.83	3.17	19.95	18.95	17.73	18.18	-0.06	31.13
29	3.22	3.53	20.99	19.48	17.73	19.86	-0.25	36.46

Degradation values in %

Day	Positive Control 1	Positive Control 2	Positive Control Mean	Test 1	Test 2	Test Mean	Abiotic Control	Toxicity Control
2	0.1	-0.1	0.0	2.4	1.9	2.1	0.6	-0.4
4	18.3	1.9	10.1	3.9	3.1	3.5	1.2	3.9
7	51.5	42.7	47.1	12.5	16.0	14.3	0.9	27.8
9	67.7	56.0	61.9	41.1	30.5	35.8	0.3	35.6
11	78.4	67.4	72.9	62.3	57.2	59.8	0.0	42.8
14	83.3	73.8	78.6	69.2	70.9	70.1	-0.1	51.1
18	83.4	78.8	81.1	71.6	73.6	72.6	-0.1	57.1
23	84.0	79.1	81.6	73.2	75.5	74.4	-0.3	69.8
29	87.4	79.9	83.6	71.4	82.0	76.7	-1.2	82.2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The following data were determined for the test item PPDA:

10-day-window: day 7 – 17
degradation at the end of 10-day-window 72 %
degradation at the end of the test 77 %
pass level following guideline: 60% at the end of 10-day-window

Therefore, when applying the 10-day-window, PPDA is readily biodegradable following OECD 301B/EU C.4-C.

Executive summary:

The test item PPDA was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 51.1 mgPPDA/L) in test medium following OECD 301B and EU-Method C.4-C.

 

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 24.9 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 62 % after nine days.

 

The following data were determined for the test itemPPDA:

 

10-day-window:                                                                                                                 day 7 – 17
degradation at the end of 10-day-window                                                                             72 %
degradation at the end of the test                                                                                            77 %
pass level following guideline:                                             60% at the end of 10-day-window

Therefore, when applying the 10-day-window, PPDA is readily biodegradable following OECD 301B/EU C.4-C.