Tributylamine

Henry's Law constant

Link to relevant study record(s)

Reference

Endpoint:

Henry's law constant

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientifically acceptable method

Reason / purpose for cross-reference:

reference to other study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Estimation of the Henry's Law Constant for the charged molecule of tributylamine (CAS 102-82-9)

GLP compliance:

no

Key result

H:

0.006 Pa m³/mol

Temp.:

25 °C

Atm. press.:

1 013 hPa

Remarks on result:

other: pH 7

Conclusions:

Henry's Law Constant: 0.00611 Pa*m³/mol at 25°C and pH 7 (estimated for the charged molecule)

Executive summary:

On the basis of the pKa and the Henry's Law Constant (HLC) of the uncharged molecule, the HLC of the charged molecule was calculated to be 0.00611 Pa*m³/mol at 25 °C and pH 7 (OXEA, 2010; ECHA, 2008).

Description of key information

The substance is not expected to evaporate from water surfaces.

Key value for chemical safety assessment

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

0.006

at the temperature of:

25 °C

Additional information

On the basis of the pKa and the Henry's Law Constant (HLC) of the uncharged molecule (47.4 Pa m^3/mol), the HLC of the charged molecule was calculated to be 0.00611 Pa*m³/mol at 25 °C and pH 7 (OXEA, 2010; ECHA, 2008).

With regard to the supporting study (Altschuh et a., 1999), a HLC of 2.48 Pm^3/mol had been determined for TBA. From the experimental section it is not possible to deduce with certainty the actual pH of the tested solution. Probably TBA was in part present as tertiary ammonium ion, such that the value may be regarded to represent a mixed population of neutral and cationic species.