Registration Dossier

Administrative data

Endpoint:
Henry's law constant
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Henry’s Law Constant states that the vapor pressure of a solute in dilute solution will be proportional to the mole fraction of the solute in the solvent. Thus, the proportionality constant is a measure of the tendency of the solute to escape from the solution. The Henry's Law Constant may be approximated as the ratio of the vapor pressure of the solid divided by the aqueous solubility.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
Purity: Not reported

Results and discussion

Henry's Law constant Hopen allclose all
Key result
H:
0 Pa m³/mol
Remarks on result:
other: In pH 4 buffer solution
Key result
H:
0 Pa m³/mol
Remarks on result:
other: In pH 7 buffer solution
Key result
H:
0 Pa m³/mol
Remarks on result:
other: In pH 9 buffer solution

Applicant's summary and conclusion

Conclusions:
The test substance has a negligible vapor pressure above dilute aqueous solutions as shown by its Henry’s Law Constant. The test substance may therefore be considered non-volatile.
Executive summary:

Henry’s Law Constant states that the vapor pressure of a solute in dilute solution will be proportional to the mole fraction of the solute in the solvent. Thus, the proportionality constant is a measure of the tendency of the solute to escape from the solution. The Henry’s Law Constant for a solute in dilute aqueous solution is expressed conventionally in units of atmospheres m3/mol and may be approximated as the ratio of the vapor pressure of the solid (in atmospheres) divided by the aqueous solubility in mol/m3.

The test substance has a negligible vapor pressure above dilute aqueous solutions as shown by its Henry’s Law Constant. In pH 4 buffer solution the constant for the test substance is 4.88 ×10e-04 Pa m3/mol or 4.81 × 10e-09 atm m3/mol. In pH 7 buffer solution the constant for the test substance is 1.22 ×10e-06 Pa m3/mol or 1.21 ×10e-11 atm m3/mol. In pH 9 buffer solution the constant for the test substance is 1.46 ×10e-07 Pa m3/mol or 1.44 ×10e-12 atm m3/mol. The test substance will have little tendency to escape from aqueous solutions, and vaporization from aqueous solutions is unlikely to contribute to dissipation of the test substance in aqueous environments. A test substance with a Henry’s Law value of less than 3 × 10e-7 atmosphere m3/mol, as it is demonstrated here for the test substance, is less volatile than water. The test substance may therefore be considered non-volatile.