Registration Dossier

Administrative data

Endpoint:
distribution modelling
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

Model:
other: EPI Suite v3.20 Level III Fugacity Model
Media:
other: air, water, soil, sediment

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Modeling was based on Reference Substance.

Results and discussion

Percent distribution in media

Air (%):
0
Water (%):
8.72
Soil (%):
89.6
Sediment (%):
1.72

Any other information on results incl. tables

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

Applicant's summary and conclusion

Conclusions:
The modeling indicates that soil is the most important environmental compartment with respect to distribution of the Reference Substance. Fast aerobic biodegradation 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 soils may allow abiotic degradation, which would proceed at faster rates than biological degradation. The low adsorption coefficient (10) indicates binding to soil will not affect 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 concentrations.   
Executive summary:

The modeling indicates that soil is the most important environmental compartment with respect to distribution of the Reference Substance. Fast aerobic biodegradation 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 soils may allow abiotic degradation, which would proceed at faster rates than biological degradation. The low adsorption coefficient (10) indicates binding to soil will not affect 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 concentrations.