2,5-xylidine

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from authoritative database and seconday source

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

To determine ready biodegradability of test substance in accordance with OECD guideline 301C (Ready Biodegradibility: Modified MITI Test (I)

GLP compliance:

not specified

Oxygen conditions:

not specified

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge:activated sludge
- Concentration of sludge: 30 mg/l

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

other: HPLC

Details on study design:

Standard type

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Remarks on result:

other: No other data available

Key result

Parameter:

% degradation (TOC removal)

Value:

0

Sampling time:

28 d

Remarks on result:

other: No other data available

Key result

Parameter:

other: HPLC

Value:

0

Sampling time:

28 d

Remarks on result:

other: No other data available

Details on results:

Percent biodegradation of test chemical was observed 0% by BOD, TOC and HPLC parameters in 28 days.

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

Percent biodegradation of test chemical was observed 0% by BOD, TOC and HPLC parameter in 28 days.Therefore it is concluded that test chemical is not readily biodegradable.

Executive summary:

The Biodegradation experiment was carried out to test biodegradability of test chemical by taking activated sludge as inoculums at 30mg/l concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC and HPLC .The initial concentration of test chemical was 100 mg/L. After 28 days of incubation percent biodegradation of test chemical was observed to be 0 % by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

Description of key information

Percent biodegradation of test chemical was observed 0% by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Following different studies includes experimental and estimated study for the target chemical as well as read-across analogues which is extracted by using mechanistic approach and functionally and structurally similar to the target chemical to observe the biodegradation rate of test chemical in water.

First study (HSDB) was conducted to assess biodegradation rate of test chemical. The Biodegradation experiment was carried out to test biodegradability of test chemical by taking activated sludge as inoculums at 30mg/l concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC and HPLC .The initial concentration of test chemical was 100 mg/L. After 28 days of incubation percent biodegradation of test chemical was observed to be 0 % by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

First experimental study for the target chemical was further supported by study from publication ( GILLES KLOPMAN. et al.)

In this study the biodegradability predicted by META was exactly the same as was observed experimentally. A computer program, META (MultiCASE, Cleveland, OH, USA) was designed and developed to help assess the susceptibility of test chemicals to biodegradation. Percent biodegradation of test chemical was predicted 1% by BOD, with the help of the MultiCASE methodology. Therefore it is concluded that test chemical is not readily biodegradable.

In next predicted data, Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical is expected to be not readily biodegradable.

Similar study(P.pitter) conducted on the test chemical for biodegradation in 20 days at 200mg /l based on decrease in COD. The biological degradability of standard test substance by specimen was performed in a batch system. The tested substance is dissolved in a beaker in a biological medium in a concentration corresponding to 200mg/l COD. The tested substance is a sole source of organic carbon for the microbes of the inoculum. To the biological medium such amount of thickened adapted activated sludge is added the beaker is placed in a dark room with a roughly constant temperature of 20 ± 3 C on an electromagnetic stirrer. Activated sludge taken from a sewage plant is cultivated in a 1000ml volumetric cylinder. The mixture is aerated with pressure air. Biodegradation of test chemical in 20 days was 96.5 % at rate of 3 .6 mg COD g-1h-1based on COD in aerobic condition. So it concluded that the test compound is readily degradable.

 In the another study( J-check) of test chemical, the Biodegradation study was carried out to test biodegradability of test chemical by taking activated sludge as inoculums at 30mg/l concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC and HPLC .The initial concentration of test chemical was 100 mg/L. After 28 days of incubation percent biodegradation of test chemical was observed to be 0 % by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

The study from the peer reviewed journel indicates that the chemical is readily biodegradable in water as adapted inoculum were used, and thus degradation was observed. But the remaining studies supports the not readily biodegradable criteria. Thus, based on the overall values, it can be concluded that the chemical is not readily biodegradable in water.