2-[2-[4-(diethylamino)phenyl]vinyl]-1,3,3-trimethyl-3H-indolium acetate

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Data is from computational model developed by USEPA

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Fugacity Model by EPI Suite estimation database

GLP compliance:

no

Radiolabelling:

no

Oxygen conditions:

other: estimation

Inoculum or test system:

not specified

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

Level III Fugacity model
EPI Suite contains a Level III fugacity model. In general, fugacity models predict the partitioning of an organic compound in an evaluative environment. A Level III model assumes steady-state but not equilibrium conditions. The Level III model in EPI Suite predicts partitioning between air, soil, sediment and water using a combination of default parameters and various input parameters that may be user defined or estimated by other programs within EPI Suite.

The model environment consists of 4 main compartments: air, water sediment and soil. There are also sub-compartments such as an aerosol phase, suspended solids, and biota phase, within specific main compartments. A fixed temperature of 25ᵒC is assumed. Mass transport between the compartments via volatilization, diffusion, deposition and runoff are modeled. level III models is a steady state, non-equilibrium model. Steady state conditions mean that the change in concentration of a chemical in each compartment (i) with respect to time eventually approaches zero. The model does not assume that a common equilibrium (fugacity) exists between the phases, so if a chemical is emitted into one compartment it can partition to the other compartments. Loss of chemical occurs through two processes: reaction and advection. Reaction is the biotic or abiotic degradation of the chemical that is calculated using the user specified or model calculated half-lives of the chemical in each of the 4 main compartments. Advection processes are considered for the air, water and sediment compartments. Advection is the removal of chemical from a compartment through losses other than degradation (reaction). The rate of advection in a given compartment is determined by a flow rate (m3/hour), calculated by dividing the volume of the compartment by an advection time.

Compartment:

water

% Recovery:

3.66

Remarks on result:

other: Other details not known

Compartment:

sediment

% Recovery:

38

Remarks on result:

other: Other details not known

Key result

% Degr.:

50

Parameter:

other: Half-life in water

Sampling time:

60 d

Key result

% Degr.:

50

Parameter:

other: Half-life in sediment

Sampling time:

541.6 d

Key result

Compartment:

water

DT50:

60 d

Type:

other: estimated data

Temp.:

25 °C

Key result

Compartment:

sediment

DT50:

541.6 d

Type:

other: estimated data

Temp.:

25 °C

Transformation products:

not specified

Evaporation of parent compound:

not specified

Volatile metabolites:

not specified

Residues:

not specified

Table 1:

	Mass Amount (percent)	half-Life (hr)	Emissions (kg/hr)
Water	3.66	1.44e+003	1000
Sediment	38	1.3e+004	0

Table 2:

	Fugacity (atm)	Reaction (kg/hr)	Advection (kg/hr)	Reaction (percent)	Advection (percent)
Water	6.73e-021	236	490	7.86	16.3
Sediment	1.12e-020	272	102	9.06	3.39

Validity criteria fulfilled:

not specified

Conclusions:

Estimated half life of test chemical in water was (60) days (1.44e+003 h) and in sediment estimated to be (541.6) days (1.3e+004 h).

Executive summary:

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 3.66 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 60 days (541.6 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 541.6 days ( 1.3e+004 hrs). Based on this half-life value, it indicates that test chemical is persistent in sediment.

Description of key information

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 3.66 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 60 days (541.6 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 541.6 days (1.3e+004 hrs). Based on this half-life value, it indicates that test chemical is persistent in sediment.

Key value for chemical safety assessment

Half-life in freshwater:

60 d

at the temperature of:

25 °C

Half-life in freshwater sediment:

541.6 d

at the temperature of:

25 °C

Additional information

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 3.66 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 60 days (541.6 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 541.6 days (1.3e+004 hrs). Based on this half-life value, it indicates that test chemical is persistent in sediment.