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Administrative data

Endpoint:
other distribution data
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: accepted calculation method

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation of volatilization from water according to Thomas RG (1990, Volatilization from water.  In: Handbook of Chemical Property Estimation Methods.  Lyman, W.J. et al. (eds), Washington, DC: American Chemical Society,  Chapter 15) based on a measured HLC (Khan and Brimblecombe 1992, see Chapt. 5.4.2)
Type of study:
other: calculation method
Media:
water - air

Test material

Constituent 1
Chemical structure
Reference substance name:
Isobutyric acid
EC Number:
201-195-7
EC Name:
Isobutyric acid
Cas Number:
79-31-2
Molecular formula:
C4H8O2
IUPAC Name:
2-methylpropanoic acid
Details on test material:
- Name of test material (as cited in study report): Propanoic acid, 2-methyl-

Results and discussion

Any other information on results incl. tables

Henry's Law Constant (HLC) at 25 °C: 8.85 E-07 atm*m³/mol = 0.0897 Pa*m³/mol

Using this HLC and the conditions indicated below the following half-lives for volatilization from rivers and lakes were calculated:

 

River 

Lake

Water depth (m)

1

1

Wind velocity (m/sec)

5

0.5

Current velocity (m/sec)

1

0.05

Half-life (hours)

621.9

6864

Half-life (days )

25.91

286

Applicant's summary and conclusion

Conclusions:
An experimental Henry's Law Constant (HLC) of 0.0897 Pa*m³/mol at 25 °C was reported from the EPIWIN database. Taking this value, volatilization half-lives of 26 and 286 days were estimated for a model river and a model lake, respectively.