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Environmental fate & pathways

Biodegradation in soil

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Reference
Endpoint:
biodegradation in soil: 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
Reference:
Composition 1
Qualifier:
according to
Guideline:
other: Modeling database
Principles of method if other than guideline:
Fugacity Model level III by EPI Suite v 4.1 estimation database
GLP compliance:
not specified
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material: 1-[(2-methoxyphenyl)azo]-2-naphthol
- Molecular formula: C17 H14 N2 O2
- Molecular weight: 278.31 g/mol
- Smiles notation: c12c(\N=N\c3c(cccc3)OC)c(ccc1cccc2)O
- InChl : 1S/C17H14N2O2/c1-21-16-9-5-4-8-14(16)18-19-17-13-7-3-2-6-12(13)10-11-15(17)20/h2-11,20H,1H3/b19-18+
- Substance type: Organic
- Physical state: solid
Radiolabelling:
not specified
Oxygen conditions:
other: estimated
Soil classification:
not specified
Parameter followed for biodegradation estimation:
test mat. analysis
Details on experimental conditions:
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.
Soil No.:
#1
% Recovery:
74.9
Remarks on result:
other: Other details not known
Key result
Soil No.:
#1
% Degr.:
50
Parameter:
other: Half-life
Sampling time:
75 d
Remarks on result:
other: Other details not known
Key result
Soil No.:
#1
Half-life:
75 d
Type:
other: estimated data
Temp.:
25 °C
Remarks on result:
other: Other details not known
Transformation products:
not specified
Evaporation of parent compound:
not specified
Volatile metabolites:
not specified
Residues:
not specified
Conclusions:
Biodegradation half-life of test substance 1-[(2-methoxyphenyl)diazenyl]-2-naphthol in soil was estimated to be 75 days (1800 hrs).
Executive summary:

The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol (CAS No. 1229 -55 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 74.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of

1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Description of key information

The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol (CAS No. 1229 -55 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 74.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of

1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Key value for chemical safety assessment

Half-life in soil:
75 d
at the temperature of:
25 °C

Additional information

The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol (CAS No. 1229 -55 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 74.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 1-[(2-methoxyphenyl)diazenyl]-2-naphthol in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of

1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.