Registration Dossier

Environmental fate & pathways

Additional information on environmental fate and behaviour

Administrative data

Endpoint:
additional information on environmental fate and behaviour
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
key study
Study period:
November 2009
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The registered material is a UVCB substance. Protperties were estimated for the reference substances, 2056-635-2. Estimtion method (EPI Suite) recommended by IUCLID Guidance Documents.

Data source

Reference
Reference Type:
other: software program
Title:
Estimation Programs Interface (EPI) Suite™ v3.20 for Microsoft® Windows,
Author:
Anonymous
Bibliographic source:
U.S. Environmental Protection Agency, Washington, DC, U.S.A.http://www.epa.gov/opptintr/exposure/pubs/episuite.htm.

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Properties of the Reference Substance were modeled using EPI Suite v3.20.
GLP compliance:
no
Type of study / information:
Environmental Fate and Distribution Properties of the Reference Substance were modeled using EPI Suite v3.20.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Modeling was based on the Reference Substance (CASRN 20566-35-2).

Results and discussion

Any other information on results incl. tables

Reference Substance Modeling Results

The modeling (Table 1) indicates that soil is the most important compartment with respect to the environmental distribution of the Reference Substance. Fast aerobic biodegradation in soil is not expected based on the STP modeling, however, anaerobic biodegradation may be possible. If applicable to soil, these results suggest the Reference Substance would not biodegrade in the upper aerobic soil levels, but may biodegrade in lower anaerobic levels or in other soil regions where anaerobic conditions exist. Further, hydrolysis is expected with half-lives of 1.363 and 13.69 days at pH 8 and 7, respectively. Thus, the moisture content in or on soils may allow abiotic degradation, which would proceed at faster rates than biological degradation. The low adsorption coefficient (10) indicates binding to soil will be low and thus should not affect biotic or abiotic degradation. 

The modeling indicates that water is the second most important environmental compartment with respect to distribution of the Reference Substance. However, hydrolysis should substantially impact any water concentrations. Predicted hydrolysis products of the Reference Substance are tetrabromophthalic acid and alcohols. 

TABLE 1. Environmental Fate Parameters for the Reference Substance using EPI Suite,

Parameter

Estimation Program

Result

5.1 Stability

Photodegradation in Air

AOP v1.92

Overall OH rate constant: 30.5163 E-12 cm3/molecule-sec

Half-life: 0.351 days (12-hr day; 1.5E6 OH/cm3)

Hlaf-life: 4.206 hours

Hydrolysis

HYDROWIN v1.67

Model used substitutes (**) for estimation. 

Ester: R1-C(=O)-O-R2. **R1: -Phenyl [3 fragments] meta:-Br, para:-Br, meta:-Br. **R2: -CH2-CH#. Ortho-postion fragments on phenyl ring not considered. Kb hydrolysis at atom#10: 4.315E+000 L/mol-sec

Ester: R1-C(=O)-O-R2.  **R1:-Phenyl [2 fragments] para:-Br, meta:-Br. **R2:-CH2-CH2-O-CH3. Ortho-postion fragments on phenyl ring not considered. Kb hydrolysis at atom#18: 1.57E+000 L/mol-sec

Total Kb for pH>8 at 25 deg C: 5.886+000 L/mol-sec

Kb Half-life at pH8: 1.363 days

Kb half-life at pH 7: 13.629 days

 

Photodegradation in Water

No Estimate

----

Photodegradation in Soil

No Estimate

----

5.2 Biodegradation

Water

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life: 1440 hours

Water and Sediment

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life in sediment: 1.296E+004 hours

Soil

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life: 2880 hours

This estimate is in accordance with measured values obtained for a structural analog, 1,2-Benzenedicarboxylic acid, 3,4,5,6-tetrabromo-, bis(2-ethylhexyl) ester (CASRN 26040-51-7).

Mode of Degradation in Actual Use

STP Fugacity Model

BIOWIN (v4.10)

Primary sludge: 12.96%, Waste Sludge 9.73%, Total Biodegradation 0.26%, Total Removal 22.95%, Final Water Effluent 77.05%

Linear Model: Does Not Biodegrade Fast

Non-Linear Model: Does Not Biodegrade Fast

Ultimate Biodegradation Timeframe: Months

Primary Biodegradation Timeframe: Weeks

MITI Liner Model: Biodegrades Fast

MITI Non-Linear Model: Does Not Biodegrade Fast

Anaerobic Model: Biodegrades Fast

Ready Biodegradation Prediction: NO

5.3 Bioaccumulation

Aquatic/Sediment Organisms

BCF v2.17

Estimated Log BCF=1.596

BCF=39.42

Terrestrial Organisms

No Estimate

----

5.4 Transport and Distribution

Adsorption/

Desorption

PCKOCWIN v1.66

10

Henry’s Law Constant, 25°C

HENRY v3.10

2.23E-021 atm-m3/mole

9.12E-20 unitless

Distribution Modeling

LEVEL III Fugacity Model

Emissions of 1000 kg/hr to air, water and soil

Air: 0.000458%, half-life 8.41 hr

Water: 8.72%, half-life 1.44E3 hr (NOTE: this half-life does not take into account the predicted hydrolysis; See HYDROLYSIS)

Soil: 89.6%, half-life 2.88E003 hr

Sediment: 1.72%, half-life 1.3E004

Other Distribution Data

KOAWIN v1.10

AEROWINv1.00

Volatilization from Water

Log Koa (octanol/air): 17.781

Koa (octanol/air): 6.035E+017

Sorption to aerosols at25°C: Kp (particle/gas partition coef.) 5.91E+003 m3/ug (Mackay model); 1.48E+005 m3/ug (Octanol/air model); Fraction sorbed to airborne particulates (phi): 1 (Junge-Pankow, Mackay, and Octanol/air models)

Half life: 6.1x10+8 years (River); 6.6x10+9 years (Lake)

Table 2. Environmental Fate Parameters for Tetrabromophthalic Acid using EPI Suite, v3.20.

Parameter

Estimation Program

Result

5.1 Stability

Photodegradation in Air

AOP v1.92

Overall OH rate constant: 1.0464 E-012 cm3/molecule-sec

Half-life: 10.222 days (12-hr day; 1.5E6 OH/cm3)

Hydrolysis

HYDROWIN v1.67

Program cannot estimate for this structure.

Photodegradation in Water

No Estimate

----

Photodegradation in Soil

No Estimate

----

5.2 Biodegradation

Water

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life: 1440 hours

Water and Sediment

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life in sediment: 1.296E+004 hours

Soil

LEVEL III Fugacity Model using Biowin Ulitmate, AOPwin

Half-life: 2880 hours

Mode of Degradation in Actual Use

STP Fugacity Model

BIOWIN (v4.10)

Primary sludge: 37.88%, Waste Sludge 24.21%, Total Biodegradation 0.57%, Total Removal 62.65%, Final Water Effluent 37.35%

Linear Model: Does Not Biodegrade Fast

Non-Linear Model: Does Not Biodegrade Fast

Ultimate Biodegradation Timeframe: Months

Primary Biodegradation Timeframe: Weeks-Months

MITI Liner Model: Biodegrades Fast

MITI Non-Linear Model: Does Not Biodegrade Fast

Anaerobic Model: Biodegrades Fast

Ready Biodegradation Prediction: NO

5.3 Bioaccumulation

Aquatic/Sediment Organisms

BCF v2.17

Estimated Log BCF=0.500

BCF=3.162

Terrestrial Organisms

No Estimate

----

5.4 Transport and Distribution

Adsorption/

Desorption

PCKOCWIN v1.66

557.3

Koc may vary with pH

Henry’s Law Constant, 25°C

HENRY v3.10

1.17E-014 atm-m3/mole

4.79E-013 unitless

Distribution Modeling

LEVEL III Fugacity Model

Emissions of 1000 kg/hr to air, water and soil

Air: 5.34E-007%, half-life 245 hr

Water: 7.362%, half-life 1.44E+03 hr

Soil: 82.8%, half-life 2.88E+03 hr

Sediment: 9.381%, half-life 1.3E+04

Other Distribution Data

KOAWIN v1.10

AEROWINv1.00

Volatilization from Water

Log Koa (octanol/air): 16.278

Koa (octanol/air): 1.897E+016

Sorption to aerosols at25°C: Kp (particle/gas partition coef.) 0.183 m3/ug (Mackay model); 4.66E+003m3/ug (Octanol/air model); Fraction sorbed to airborne particulates (phi): 0.869 Junge-Pankow, 0.936 Mackay, and 1 Octanol/air models.

Half life: 1.253x10+007 years (River); 1.367x10+008 years (Lake)

Applicant's summary and conclusion

Conclusions:
The modeling (Table 1) indicates that soil is the most important compartment with respect to the environmental distribution of the Reference Substance. Fast aerobic biodegradation in soil is not expected based on the STP modeling, however, anaerobic biodegradation may be possible. If applicable to soil, these results suggest the Reference Substance would not biodegrade in the upper aerobic soil levels, but may biodegrade in lower anaerobic levels or in other soil regions where anaerobic conditions exist. Further, hydrolysis is expected with half-lives of 1.363 and 13.69 days at pH 8 and 7, respectively. Thus, the moisture content in or on soils may allow abiotic degradation, which would proceed at faster rates than biological degradation. The low adsorption coefficient (10) indicates binding to soil will be low and thus should not affect biotic or abiotic degradation. 

The modeling indicates that water is the second most important environmental compartment with respect to distribution of the Reference Substance. However, hydrolysis should substantially impact any water concentrations. Predicted hydrolysis products of the Reference Substance are tetrabromophthalic acid and alcohols. 
Executive summary:

The modeling (Table 1) indicates that soil is the most important compartment with respect to the environmental distribution of the Reference Substance. Fast aerobic biodegradation in soil is not expected based on the STP modeling, however, anaerobic biodegradation may be possible. If applicable to soil, these results suggest the Reference Substance would not biodegrade in the upper aerobic soil levels, but may biodegrade in lower anaerobic levels or in other soil regions where anaerobic conditions exist. Further, hydrolysis is expected with half-lives of 1.363 and 13.69 days at pH 8 and 7, respectively. Thus, the moisture content in or on soils may allow abiotic degradation, which would proceed at faster rates than biological degradation. The low adsorption coefficient (10) indicates binding to soil will be low and thus should not affect biotic or abiotic degradation. 

The modeling indicates that water is the second most important environmental compartment with respect to distribution of the Reference Substance. However, hydrolysis should substantially impact any water concentrations. Predicted hydrolysis products of the Reference Substance are tetrabromophthalic acid and alcohols.