2-Propanamine, compd. with boron trifluoride, reaction products with Bu glycidyl ether

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

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms was obtained on 19 September 2016 from the aeration stage of the Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, UK, which treats predominantly domestic sewage.
Preparation of Inoculum
The activated sewage sludge sample was washed twice by settlement and re-suspension in mineral medium to remove any excessive amounts of dissolved organic carbon (DOC) that may have been present. The washed sample was then maintained on continuous aeration in the laboratory at a temperature of approximately 21 ºC and used on the day of collection.
Determination of the suspended solids level of the activated sewage sludge was carried out by filtering a sample (100 mL) of the washed activated sewage sludge by suction through pre-weighed GF/A filter paper* using a Buchner funnel. Filtration was then continued for a further 3 minutes after rinsing the filter three successive times with 10 mL of deionized reverse osmosis water. The filter paper was then dried in an oven at approximately 105 ºC for at least 1 hour and allowed to cool before weighing. This process was repeated until a constant weight was attained. The suspended solids concentration was equal to 3.0 g/L prior to use.

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The following test preparations were prepared and inoculated in 5 liter test culture vessels each containing 3 liters of solution:
a) An inoculated control, in duplicate, consisting of inoculated mineral medium.
b) The procedure control containing the reference item (sodium benzoate), in duplicate, in inoculated mineral medium to give a final concentration of 10 mg carbon/L.
c) The test item, in duplicate, in inoculated mineral medium to give a final concentration of 10 mg carbon/L.
d) The test item plus the reference item in inoculated mineral medium to give a final concentration of 20 mg carbon/L to act as a toxicity control (one vessel only).
Data from the inoculum control and procedure control vessels was shared with similar concurrent studies.
Each test vessel was inoculated with the prepared inoculum at a final concentration of 30 mg suspended solids (ss)/L. The test was carried out in a temperature controlled room at temperatures of between 22 and 24 °C, in darkness.
Approximately 24 hours prior to addition of the test and reference items the vessels were filled with 2400 mL of mineral medium and 30 mL of inoculum and aerated overnight. On Day 0 the test and reference items were added and the pH of all vessels measured using a Hach HQ40d Flexi handheld meter. If necessary the pH was adjusted to pH 7.4 ± 0.2 using diluted hydrochloric acid or sodium hydroxide solution prior to the volume in all the vessels being adjusted to 3 liters by the addition of mineral medium which had been purged overnight with CO2 free air.
The test vessels were sealed and CO2-free air bubbled through the solution at a rate of 30 to 100 mL/min per vessel and stirred continuously by magnetic stirrer.
The CO2-free air was produced by passing compressed air through a glass column containing self-indicating soda lime (Carbosorb®) granules.
The CO2 produced by degradation was collected in two 500 mL Dreschel bottles containing 350 mL of 0.05 M NaOH. The CO2 absorbing solutions were prepared using purified water.

Reference substance:

benzoic acid, sodium salt

Preliminary study:

The results obtained from the samples taken for DOC analysis from the preliminary investigational work indicated that the test item did not adsorb to filter matrices or to activated sewage sludge (see Annex 3). Therefore, for the purpose of the study, the samples taken for DOC analysis were filtered to remove the suspended solids present without the loss of any test item.

Test performance:

Inorganic carbon values for the test item, procedure control, toxicity control and inoculum control vessels at each analysis occasion were recorded. Percentage biodegradation values of the test item are given in next section. Percentage biodegradation values of the reference items and the toxicity control are given in attached table.

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

0 d

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

2 d

Parameter:

% degradation (CO2 evolution)

Value:

16

Sampling time:

6 d

Parameter:

% degradation (CO2 evolution)

Value:

24

Sampling time:

8 d

Parameter:

% degradation (CO2 evolution)

Value:

25

Sampling time:

10 d

Parameter:

% degradation (CO2 evolution)

Value:

19

Sampling time:

14 d

Parameter:

% degradation (CO2 evolution)

Value:

29

Sampling time:

21 d

Parameter:

% degradation (CO2 evolution)

Value:

27

Sampling time:

28 d

Parameter:

% degradation (CO2 evolution)

Value:

30

Sampling time:

35 d

Remarks on result:

other:

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Boron (2-propanamine) trifluoro-, rxn prod with butyl glycidyl ether attained 27% biodegradation after 28 days and 28% biodegradation after 35 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301B.

Executive summary:

Boron (2-propanamine) trifluoro-, rxn prod with butyl glycidyl ether attained 27% biodegradation after 28 days and 28% biodegradation after 35 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301B.

Description of key information

Boron (2-propanamine) trifluoro-, rxn prod with butyl glycidyl ether attained 27% biodegradation after 28 days and 28% biodegradation after 35 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301B.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable