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Environmental fate & pathways

Henry's Law constant

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Description of key information

From the water surface the test item (represented by C13H29N, C23H49N, C26H55N and C29H61N) will not evaporate into the atmosphere.

Key value for chemical safety assessment

Henry's law constant (H) (in Pa m³/mol):
0.239
at the temperature of:
25 °C

Additional information

Regarding the main fraction of the mixture (C26H55N, represented by di-iso-tridecylamine, CAS 57157 -80 -9)

a Henry's Law Constant (HLC) of 1.51E03 Pa*m³/mol was calculated for the uncharged form with the bond estimation method (EPISUITE v4.10; BASF, 2011). Using the method described in the REACH Guidance Document R7a, Appendix R.7.1-2 (pH correction of partition coefficients for ionisable substances, p. 189), this HLC was corrected for the charged molecule to a value of 0.239 Pa*m³/mol at pH 7 (BASF, 2011).

Regarding the other compounds of the test item (CAS 101 012 -97 -9), the range of the HLC for molecules with a C-chain length between C13 and C29 is expected to be < 1 Pa*m³/mol at pH 7 (0.00537 - 0.561 Pa*m³/mol).

SMILES code

Mol. formula

CAS No.

Input parameter

Corrected HLC *

HLC * (uncharged)

pKa **

pH 4***

pH 7

pH 9

NCCCCCCCCCCC(C)C

C13H29N1

35723-81-0

2.30E+01

10.41

8.95E-06

8.94E-03

8.61E-01

C(C)(C)CCCCCCCCNCCCCCCCCCC(C)C

C23H49N1

-

6.47E+02

10.80

1.03E-04

1.03E-01

1.01E+01

CC(C)CCCCCCCCCCNCCCCCCCCCCC(C)C

C26H55N1

57157-80-9

1.51E+03

10.80

2.39E-04

2.39E-01

2.36E+01

CC(C)CCCCCCCCCCCCCCNCCCCCCCCCC(C)C

C29H61N1

-

3.54E+03

10.80

5.61E-04

5.61E-01

5.52E+01

* HLC = Henry’s Law Constant in Pa*m³/mol (at 25 °C)

** pKa from SPARC estimation (see chapter 4.21)

*** The calculation for pH 4.0 is considered to be of low relevance. At pH 7.0 the substance is almost entirely in its charged form due to the pKa of 10.41 (C13-monoalkylamine) and 10.8 (C23-C29-dialkylamines). Therefore, at pH 4.0 no further significant reduction of the HLC compared to the values at pH 7.0 is expected. 

In conclusion, the HLC of the uncharged molecule is expected to be < 1 Pa*m³/mol (pH 7, 25°C). Therefore, significant evaporation of the substance from water is unlikely.