N-methyl-P,P-bis(2-methylaziridin-1-yl)phosphinamide

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2018-10-16 to 2018-11-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Principles of method if other than guideline:

Not relevant.

GLP compliance:

yes (incl. QA statement)

Remarks:

Signed in November 2017

Specific details on test material used for the study:

FCBA reference: 1711228F11
Batch number:1 00001 0405
Manufacturing date: June 15,2017
CAS number: No.85068-72-0
Nominal content of the active substance: 97.5 % wlw
Manufacturer: ARIANEGROUP SAS
Test item physical state: Solid whitish cast
Test item quantity received at test facility: 300 g
Reception date: November 06,2017
Storage conditions: Fridge
Stability : re-inspection date: May 02, 2019

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Sample site : Water Treatment Plant "STEP de LILLE", 33290 Blanquefort (France)
Date of sampling: October 11, 2018
Suspendid solid: 3.34 g/L
pH: 6.7
Dissolved oxygen: 8.9 mg/L

Activated sludge preparation:
1) Filtration through a 1 mm sleve
2) 3 successive decantations into mineral medium
3) Activated sludge aeration during 5 days

The inoculum was a fresh sample of activated sludge and was collected from the aeration tank of a sewage treatment plant receiving predominantly domestic sewage.
A filtration through a fine sieve (about 1 mm) was performed in order to remove coarse paruoes. After removal of any coarse particles, the sludge was washed by decantation in a mineral medium until sludge was considered free from excess substrate or inhibitor

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Remarks:

Loading rate

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS

Mineral medium:
- Na2HPO4, 2H20 334 mg/l
- Cacl2, 2H2O 36.4mg/l
- K2HPO4 217.5 mg/l
- MgSO4, 7H2O 22.5mg/l
- NH4Cl 5mg/l
- FeCl3, 6H2O 0.25 mg/l
- KH2P04 85 mg/l

TEST SYSTEM
- Culturing apparatus:
- Number of culture flasks/concentration:
- Inoculum control ( inoculum only): 3
- test item 100 mg/L (test item +inoculum): 3
- Reference item (Sodium benzoate and inoculum) : 2
- Toxicity control (test item, sodium benzoate and inoculum): 2

Solution of Sodium Benzoate at 1 g/L: weighing of 200.01 mg in 200ml mineral medium

STATISTICAL METHODS:
The oxygen consumption was automatically recorded for each flask: data were reported in a spreadsheet program.

Reference substance:

benzoic acid, sodium salt

Preliminary study:

None.

Parameter:

% degradation (O2 consumption)

Value:

13.72

Sampling time:

28 d

Remarks on result:

other: Based on ThOD NH4

Parameter:

% degradation (O2 consumption)

Value:

8.41

Sampling time:

28 d

Remarks on result:

other: based on ThOD NO3

Details on results:

The test item "METHYL BAPO" contains nitrogen according to the elementary analysis, the evaluation of biodegradation has to be based in the following expressed as ThODNH4 and ThODNO3.

Following the ThODNH4, the degradation for the 10-day window failed.
The degradation rate of the test item "METHYL BAPO" reached 13.72% (10.80% to 17.83%), following the Th0DNH4, after 28 days of incubation.

Following the ThODNO3, the degradation for the 10-day window failed.
The degradation rate of the test item "METHYL BAPO" reached 8.41% (6.62% to 10.92%), following the ThODNO3, after 28 days of incubation.
Under conditions of OECD Guideline 301 F, the test item "METHYL BAPO", is not considered to be readily biodegradable.

Results with reference substance:

The reference item "Sodium benzoate" was degraded up to 88.13% and 99.50% after 14 days. Therefore, it confirms the suitability of the used aerobic sludge inoculum.

Biodegradation of the Toxlcity Control

A biodegradation of 38.59% and 37.06% after 14 days of incubation was noted in the Toxicity control  (containing  both of the test item and the reference item) based on ThODNH4,

A biodegradation  of 27.78% and 26.68% after 14 days of incubation was noted in the Toxicity control (containing  bath of the test item and the reference item) based on ThODNO3.

Therefore,  the test item was not inhibitory at the tested concentration on the aerobic activated sludge micro-organism because degradation was superior to 25% within 14 days (validity criterion).

Validity criteria:

Criteria	Validity for OECD 301F	Validity for the test
Variation between the test item replicatesat28 days	< 20%	Cv = 26.68% (with ThODNH4) Cv = 26.64% (with ThODNO3)
Biodegradability of the toxicity control within 14 days	> 25%	Yes ( 38.59% and 37.06% with ThODNH4) Yes ( 27.78% and 26.68% with ThODNO3)
Oxygen uptake of the inoculum control in 28 days	< 60 mg/L	Yes (12.7 to 21.1 mg/L)
Biodegradability of the reference item within 14 days	> 60%	Yes (93.82%)
pH of the inoculum control at 28 days	6 to 8.5	Yes (7.5)

All the validity criteria were successful except the variation  between the test item replicates at 28 days.

Deviation:

One deviation to the study plan 17/1228F/g was observed in this study:

The variation between the test item replicates at the end of the test was higher than 20 % (Cv=26.68% with ThODNH4 and 26.64% with ThODNO3).  Nethertheless, the test item is not considered  readily biodegradable whatever the replicates.

This deviation has no incidence on study results.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Based on ThODNH4, the 10-Day window failed and the degradation rate of the test item "METHYL BAPO" is 13. 72% after 28 days of incubation.
Based on ThODNO3, the 10-Day window failed and the degradation rate of the test item "METHYL BAPO" is 8.41 % after 28 days of incubation.

The results obtained show that the test item is not considered to be readlly biodegradable following the ThODNH4 and the ThODNO3, after 28 days of incubation.
Under conditions of OECD Guideline 301F, the test item "METHYL BAPO", is not considered to be readily biodegradable whatever the ThOD.

Executive summary:

The aim of this study was to determine the biodegradability of the test item "METHYL  BAPO" according to the OECD 301 F guideline, within an experimental  period up to 28 days by respirometric method.

The amount of oxygen taken up by the microbial population during the biodegradation of the test item (corrected  by blank inoculum, run in parallel) was determined  from the change in pressure in apparatus and will be expressed as percentage of theoretical Oxygen Demand (ThOD).

All the validity criteria were successful except the variation between the test item replicates at 28 days.

Based on ThODNH4, the 10-Day window failed and the degradation  rate of the test item "METHYL BAPO" is 13. 72% after 28 days of incubation.

Based on ThODNO3, the 10-Day window failed and the degradation  rate of the test item "METHYL BAPO" is 8.41 % after 28 days of incubation.

The results obtained show that the test item is not considered to be readily biodegradable following  the ThODNH4 and the ThODNO3, after 28 days of incubation.

Description of key information

The ready biodegradability of the substance has been investigated during an OECD 301F study.

The substance has been found to be not readily biodegradable with degradation rates of 13.72% and 8.41% at 28 days based on ThODNh4 and on ThODNO3, respectively.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The aim of the experiemental study was to determine the biodegradability of the test item "METHYL  BAPO" according to the OECD 301 F guideline, within an experimental  period up to 28 days by respirometric method.

The amount of oxygen taken up by the microbial population during the biodegradation of the test item (corrected  by blank inoculum, run in parallel) was determined  from the change in pressure in apparatus and will be expressed as percentage of theoretical Oxygen Demand (ThOD).

All the validity criteria were successful except the variation between the test item replicates at 28 days.

Based on ThODNH4, the 10-Day window failed and the degradation  rate of the test item "METHYL BAPO" is 13. 72% after 28 days of incubation.

Based on ThODNO3, the 10-Day window failed and the degradation  rate of the test item "METHYL BAPO" is 8.41 % after 28 days of incubation.

The results obtained show that the test item is not considered to be readily biodegradable following  the ThODNH4 and the ThODNO3, after 28 days of incubation.