Hexafluoropropene, oxidized, oligomers, reduced, fluorinated

Henry's Law constant

Link to relevant study record(s)

Reference

Endpoint:

Henry's law constant

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Study period:

not applicable

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

other: Guidance on Information Requirements and Chemical Safety Assessment_Chapter R.7a: Endpoint specific guidance_version 3

Qualifier:

according to guideline

Guideline:

other: Guidance on Information Requirements and Chemical Safety Assessment_ Chapter R.16: Environmental Exposure Estimation_ Version 2.1

Principles of method if other than guideline:

Henry's Law constant is calculated from the ratio of the vapour pressure to the water solubility.

H:

13 792 979 Pa m³/mol

Temp.:

20 °C

Remarks on result:

other: calculated

H:

20 660 426 Pa m³/mol

Temp.:

20 °C

Remarks on result:

other: calculated

Conclusions:

The Henry's Law constant of GALDEN LMW at 20°C, calculated for the two GALDEN LMW grades is:
HLC = 20660426Pa m3/mol
HLC =13792979Pa m3/mol

Executive summary:

The HENRY Law constant of GALDEN LMW has been calculated according to the following equation:

HLC = (VP x molW) / Water Solubility

(Reference: Guidance on Information Requirements and Chemical Safety Assessment_ Chapter R.16: Environmental Exposure Estimation_ Version 2.1_Equation R.16-4)

 

The Henry's Law constant of GALDEN LMW, calculated for the two GALDEN LMW grades is resulted to be:

HLC = 20660426 Pa m3/mol (at 20°C)

HLC =13792979 Pa m3/mol (at 20°C)

The typical mean values as used as calculation parameters.

 

The results indicate that both the GALDEN LMW grades have the same magnitude of volatilization.

Description of key information

The HENRY Law constant of GALDEN LMW has been calculated according to the equation: HLC = (VP x molW) / Water Solubility.
The results indicate that GALDEN LMW has a very high tendency to distribute from water to the air. Volatilisation of GALDEN LMW from water is expected to be extremely rapid.

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):

17 226 702.5

at the temperature of:

20 °C

Additional information

Galden is a multi-constituent substance consisting of low molecular weight perfluoropolyethers (PFPE). Two grades of Galden LMW are manufactured (Galden HT55 and HT70), which contain the same perfluorinated constituents and differ only in the relative concentration of the constituents.

The Henry's Law constant of GALDEN LMW, calculated according to the equation: HLC = (VP x molW) / WS for the two GALDEN LMW grades, results to be:

HLC (HT 55) = 20660426 Pa m3/mol (at 20°C)

HLC (HT 70) =13792979 Pa m3/mol (at 20°C) 

(Reference: Guidance on Information Requirements and Chemical Safety Assessment_ Chapter R.16: Environmental Exposure Estimation_ Version 2.1_Equation R.16-4)

 

The values indicates that GALDEN LMW has a very high tendency to distribute from water to the gas phase.

As reported in Guidance on Information Requirements and Chemical Safety Assessment_Chapter R.7a,substances with HLC values around 100 Pa·m3/mol, will have a rapid volatilisationfrom water. Basing on the calculated Henry’s Law constant value, volatilization of GALDEN LMW from water is expected to be extremely rapid.

The calculated average value HLC =17226702,5 Pa m3/mol (at 20°C) for Galden HT70 and GALDEN HT55 has been set as key value for risk assessment purpose.