Reaction mass of m-terphenyl and o-terphenyl

Distribution modelling

Administrative data

Endpoint:

distribution modelling

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2018-04-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
Estimation Programs Interface (EPI) Suite for Microsoft Windows, v4.11 (US EPA, 2012)

2. MODEL (incl. version number)
LEV3EPI™

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
c1cc(ccc1)c1cccc(c1)c1ccccc1, also refer to section 'Test material'

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF.

5. APPLICABILITY DOMAIN
See attached QPRF.

6. ADEQUACY OF THE RESULT
- The model is scientifically valid (see attached QMRF).
- The model predicts partitioning of chemicals among air, soil, sediment, and water under steady state conditions for a default model "environment".
(mass amounts for the 4 compartments, the corresponding half-lives and the overall persistence, see also attached QPRF).
- See attached QPRF for reliability assessment.

Data source

Reference

Reference Type:

other: QSAR

Title:

Unnamed

Materials and methods

Model:

calculation according to Mackay, Level III

Calculation programme:

The fugacity was determined using EQC Level III Fugacity model as found in EPIWIN  4.11. All physical constants where calculated by Epiwin.
Degradation in  air, water, soil and sediment was determined from the BIOWIN (ultimate) and the AOPWIN program. Direct photolysis was not considered in this model. Other parameters used the default values found in EPIWIN.

Release year:

2 012

Media:

other: air - water - soil - sediment

Test material

Test material information

Constituent 1

Reference substance name:

m-terphenyl

EC Number:

202-122-1

EC Name:

m-terphenyl

Cas Number:

92-06-8

Molecular formula:

C18H14

IUPAC Name:

1,1':3',1''-terphenyl

Specific details on test material used for the study:

SMILES: c1cc(ccc1)c1cccc(c1)c1ccccc1

Study design

Test substance input data:

SMILES: c1cc(ccc1)c1cccc(c1)c1ccccc1
CAS number: 92-06-8
EC number: 202-122-1
Chemical name:
a. 1,1':3',1''-Terphenyl
b. m-Terphenyl
Molecular formula: C18H14
Molecular Wt:       230.31
Henry's LC:          3.38e-005 atm-m3/mole (Henrywin program)
Vapor Press:         1.64e-005 mm Hg (Mpbpwin program)
Liquid VP:             0.000115 mm Hg (super-cooled)
Melting Pt:             111 deg C (Mpbpwin program)
Log Kow:              5.52 (Kowwin program)
Soil Koc:               1.81e+005 (KOCWIN MCI method)

- BIOWIN (Ultimate) estimate: 3.2 (weeks)
- Reaction half-life estimates for
- Air: 3.24 h (AOPWIN)
- Water: 360 h (based upon BIOWIN (Ultimate))
- Soil: 720 h (based upon BIOWIN (Ultimate)
- Sediment: 3240 h (based upon BIOWIN (Ultimate))

Environmental properties:

see "Any other information on materials and methods incl. tables"

Results and discussion

Percent distribution in media

Air (%):

0.407

Water (%):

5.92

Soil (%):

44.2

Sediment (%):

49.5

Any other information on results incl. tables

Level III Fugacity Model (Full-Output):

=======================================

Chem Name:        m-Terphenyl

Molecular Wt:       230.31

Henry's LC:          3.38e-005 atm-m3/mole (Henrywin program)

Vapor Press:         1.64e-005 mm Hg (Mpbpwin program)

Liquid VP:             0.000115 mm Hg (super-cooled)

Melting Pt:             111 deg C (Mpbpwin program)

Log Kow:              5.52 (Kowwin program)

Soil Koc:               1.81e+005 (KOCWIN MCI method)

Mass Amount       Half-Life       Emissions

(percent)              (hr)               (kg/hr)

Air         0.407                   20.3              1000

Water     5.92                    900               1000

Soil        44.2                    1.8e+003      1000

Sediment 49.5                    8.1e+003      0

Compartment	Fugacity	Reaction	Advection	Reaction	Advection
	(atm)	(kg/hr)	(kg/hr)	(percent)	(percent)
Air	2.54e-011	823	241	27.4	8.03
Water	2e-010	270	350	8.99	11.7
Soil	4.92e-012	1.01e+003	0	33.6	0
Sediment	2.48e-010	251	58.6	8.36	1.95

 

Persistence Time	1.97e+003 hr
Reaction Time	2.52e+003 hr
Advection Time	9.11e+003 hr
Percent Reacted	78.3
Percent Advected	21.7

Half-Lives (hr), (based upon Biowin (Ultimate) and Aopwin):

Air:               20.28

Water:          900

Soil:              1800

Sediment:       8100

Biowin estimate: 2.734 (weeks-months)

Advection Times (hr):

Air:                     100

Water:               1000

Sediment:            5e+004

Applicant's summary and conclusion

Conclusions:

The report describes a scientifically accepted calculation method to determine the soil adsorption coefficient using the US-EPA software EPIWIN/LEVEL3NT.EXE. No GLP criteria are applicable for the usage of this tool and the QSAR estimation is easily repeatable. The percentages of distribution in media are: 0.407% in air, 5.92 % in water, 44.2 % in soil and 49.5 % in sediment.
The half-lives of m-terphenyl are: 20.28 hours in air, 900 hours (ca. 38 days) in water, 1800 hours (75 days) in soil and 8100 hours (ca. 338 days) in sediment.

Executive summary:

Distribution modelling for m-terphenyl was performed. The Level III fugacity model of the scientifically accepted computer program EPIWIN by US-EPA was used for this purpose. The executable file is called LEVEL3NT.EXE.The software is no stand-alone version and it contains a direct adaption of the Level III fugacity model developed by Mackay (1991) and Mackay et al. (1996). Level III modelling assumes a steady-state, but no common equilibrium conditions between the different environmental compartments. Four main compartments are concerned: air, water, sediment and soil. Between these compartments, mass transport is modeled via volatilization, diffusion, deposition and runoff. A fixed temperature of 25 °C is assumed.No substance properties are entered manually, thus default values are used.

In general, disappearance of a chemical occurs via two processes: reaction and advection. The abiotic or biotic degradation belongs to reaction, whereas the removal from a compartment through losses other than degradation is called advection. The rate of advection is determined by a specific flow rate, which may be specified by the user. Furthermore, the user can specify emission rates; otherwise the default emission rate is equal amounts to air, water and soil. For the sediment compartment, no direct emissions are considered.If half-lives in the different compartments are known, the values should be entered manually. Otherwise, EPIWIN software BIOWIN (Biowin 3 – Ultimate Biodegradation Timeframe) and AOPWIN are used to make these estimations by default. If a chemical is susceptible to abiotic hydrolysis, HYDROWIN may be able to provide the half-life.If a combination of hydrolysis, photolysis and biodegradation is likely for the compound, the half-lives shall be converted to rate constants and added together. The resulting overall half-life should be entered into the modelling.The output of Biowin 3 cannot be used directly by the Level III mass balance model. The mean value is converted to a half-life using a set of conversion factors, which consider that 6 half-lives constitute complete degradation with first-order kinetics.

Ultimate biodegradation is generally slower under anaerobic conditions than under aerobic conditions. The program concerns aerobic conditions; only for sediment an anaerobic environment is assumed. The rate of ultimate degradation in sediment is on average one-ninth (1/9) of that in the water column. A further adjustment is taken into account: In general, the biodegradation rate in soil is, on average, one-half (1/2) that in water. Therefore, a half-life in soil twice that estimated for water is assigned. The default environmental emission rates are 1000 kg/h to air, water and soil (sediment: 0 kg/h), which may be altered manually.The advection lifetimes of the substance in air, water and sediment compartments are set to the default values of 100, 1000 and 50000 hours, respectively. These lifetimes are used to determine the advective flow rate (m³/h). If no advection to any compartment is expected, the lifetime should be set to some arbitrarily large value (such as 1E20); this effectively changes the advective flow rate to zero. A soil Koc value is also required for the fugacity model. By default, the connectivity-based adsorption coefficient is used (MCI result by KOCWIN).

For this calculation the default of 1.5E+6 OH radicals/cm³ and a 12 -hrs day was used.

Concerning m-terphenyl, for the 4 compartments, i.e. air, water, soil and sediment, the following mass amounts are predicted for the representative structure: 0.407 % (air), 5.92 % (water), 44.2 % (soil) and 49.5 % (sediment), respectively. The corresponding half-lives in the different compartments are predicted as: 20.28 h (air), 900 h (water; ca. 38 days), 1800 h (soil; ca. 75 days) and 8100 h (sediment; ca. 338 days), respectively. The overall persistence time gives a measure of how long the chemical remains in the model environment and is estimated as 1970 h (ca. 82 days) for the test substance.