1,1'-(ethane-1,2-diyl)bis[pentabromobenzene]

Distribution modelling

Administrative data

Endpoint:

distribution modelling

Type of information:

(Q)SAR

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Study period:

April 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Estimated performed using software recommended by REACH Guidance.

Data source

Reference

Reference Type:

other: software program

Title:

EPI v3.20. (February 2007. Estimation Programs Interface. U.S. Environmental Protection Agency Office of Pollution Prevention and Toxic Substances. Syracuse Research Corporation).

Author:

anonymous

Year:

2007

Bibliographic source:

U.S. Environmental Protection Agency, Washington, D.C.

Materials and methods

Model:

calculation according to Mackay, Level III

Calculation programme:

Level III Fugacity Model, EPIwin v3.20

Release year:

2 007

Media:

other: air, water, soil, sediment

Test material

Test material information

Constituent 1

Reference substance name:

1,1'-(ethane-1,2-diyl)bis[pentabromobenzene]

EC Number:

284-366-9

EC Name:

1,1'-(ethane-1,2-diyl)bis[pentabromobenzene]

Cas Number:

84852-53-9

Molecular formula:

C14H4Br10

IUPAC Name:

1,2,3,4,5-pentabromo-6-[2-(2,3,4,5,6-pentabromophenyl)ethyl]benzene

Details on test material:

Modeled on DBDPEthane's chemical structure

Study design

Test substance input data:

Chemical structure was input into EPI.

Environmental properties:

Default model parameters

Results and discussion

Percent distribution in media

Air (%):

0.05

Water (%):

0.6

Soil (%):

48.8

Sediment (%):

50.5

Aerosol (%):

0

Any other information on results incl. tables

Predicted Transport and Distribution Between Environmental Compartments

DBDPEthane’s transport and distribution between environmental compartments was modeled using EPI v. 3.20, and based on the chemical’s structure. In the environment, 99.3% of DBDPEthane's releases are predicted to distribute to sediment and soil. DBDPEthane is predicted to partition to sediment (50.5%) and soil (48.8%) with negligible amounts partitioning to water (0.6%) and air (0.05%) (Level III Fugacity Model; Emissions of 1000 kg/hr to each of air, water, soil).  It is expected to bind extensively to organic carbon based on estimated Koc values (Table), and therefore to be essentially immobile in soil, sewage sludge, and sediments. It is not expected to volatilize from water (Volatilization half-life in rivers = 7 years, in lakes = 77 years). In air, it is expected to bind to airborne particulates. The fraction sorbed to particulates is estimated to be 1 at 25°C (AEROWIN v1.00). Its characteristic travel distance is expected to be low, which indicates it should not be subject to long-range transport in the atmosphere. Its movement in the atmosphere will be governed by that of the particulates to which it is bound.

Removal in sewage treatment plants is expected (94% total removal) through settling in sludge (60% in primary sludge, 33% in waste sludge) (STP Fugacity Model). Aerobic biodegradation in a sewage treatment plants is not expected. The amount in the final water effluent leaving a treatment plant is estimated at approximately 6% of the influent. 

Estimated Properties for DBDPEthane using EPI (v3.20).

Property	Result	EPI Module
Henry’s Law Constant (25ºC)	6.42 x 10^-8atm-m3/mole (Bond) 2.94 x 10^-8atm-m3/mole (Group)	HENRY (v3.10)
	2.94 x 10^-8atm-m3/mole 1.20 x 10^-6unitless	HENRYWIN v3.10
	2.09 x 10^-1atm-m3/mole	VP/Wsol Estimate using EPI values
Liquid/Subcooled Vapor Pressure	9.33 x 10^-9Pa 7 x 10^-11Hg	AEROWIN v1.00
Log Koa (octanol/air partition coefficient)	19.221	KOAWIN v1.10
Log Kaw (air/water partition coefficient)	-5.581	KOAWIN v1.10
Particle/gas Partition Coefficient (Kp) (m3/μg)	321 (Mackay model) 4.08 x10^6(Koa model)	AEROWIN v1.00
Reaction with Hydroxyl Radicals in the Atmosphere	Overall OH Rate Constant = 2.395 x10^-12cm3/molecule-sec; Half-life = 4.466 days (12-hr d; 1.5x10^6OH/cm3)	AOP v1.92
Koc	3.312 x 10^6	PCKOC (v1.66)
Biomass to water partition coefficient	8.73 x 10^12	STP Fugacity Model

Applicant's summary and conclusion

Conclusions:

DBDPE is expected to partition in the environment to sediment and soil (ca. 99%). High binding to particulates in all media is expected. Sewage treatment plants are expected to remove > 95% of that present in the influent. Removal is expected to be via binding to particulates rather than biodegradation. Its characteristic travel distance is expected to be low and long range atmospheric transport is not expected. Its movement in the atmosphere will be governed by the particulates to which it is bound.

Executive summary:

DBDPE is expected to parition in the environment to sediment and soil (ca. 99%). High binding to particulates in all media is expected. Sewage treatment plants are expected to remove > 95% of that present in the influent. Removal is expected to be via binding to particulates rather than biodegradation. Its characteristic travel distance is expected to be low and long range atmospheric transport is not expected. Its movement in the atmosphere will be governed by the particulates to which it is bound.