ethametsulfuron-methyl (ISO); methyl 2-[(4-ethoxy-6-methylamino-1,3,5-triazin-2-yl)carbamoylsulfamoyl]benzoate

Henry's Law constant

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

Test material information

Constituent 1

Reference substance name:

Reference substance 002

Cas Number:

97780-06-8

Test material form:

solid

Details on test material:

Purity: Not reported

Results and discussion

Henry's Law constant H

Henry's Law constant H 1

Key result

H:

0 Pa m³/mol

Remarks on result:

other: In pH 4 buffer solution

Henry's Law constant H 2

Key result

H:

0 Pa m³/mol

Remarks on result:

other: In pH 7 buffer solution

Henry's Law constant H 3

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.