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Description of key information

The Henry's Law constant for MeaTG estimated as 7.354*10-6 Pa*m3/mol (7.26*10-6 atm*m3/mol) indicates that MeaTG is expected to be essentially nonvolatile from water surfaces and that volatilization from moist soil surfaces may not occur.  

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):
0
at the temperature of:
25 °C

Additional information

The Henry's Law constant were estimated according to the Handbook of Chemical Property Estimation Methods (Lyman, 1990) using the measured values of water solubility and vapour pressure of MeaTG.

The Henry's Law constant [via Vp/Wsol estimate using the measured values from section 4.6 and 4.8]:

H = 7.257*10-11 atm*m3/mol (7.354*10-6 Pa*m3/mol)

VP: 0.00036 mm Hg (IUCLID section: 4.6)

WS: 1000 g/L (source: IUCLID section: 4.8)

The Henry's Law constant for MeaTG estimated as 7.354*10-6 Pa-m3/mol (7.257*10-11 atm*m3/mol) indicates that MeaTG is expected to be essentially nonvolatile from water surfaces and that volatilization from moist soil surfaces may not occur. MeaTG is not expected to volatilize from dry soil surfaces based upon an estimated vapour pressure of 0.048 Pa (3.6*10-4 mm Hg). The water solubility of MeaTG is > 1000 g/L.

A pKa of 3.8 for thioglycolic acid also indicates that volatilization from water will not be an important environmental fate process as it will exist predominately in the ionic form under environmental pHs.