Gases (petroleum), light steam-cracked, butadiene conc.

Henry's Law constant

Link to relevant study record(s)

Reference

Reference 1

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: QSAR calculation, acceptable with restrictions

Justification for type of information:

Two QSAR methods recommended by ECHA (2008) Guidance on information requirements and chemical safety assessment R7a Endpoint specific guidance.

Principles of method if other than guideline:

HENRYWIN v3.2 in EPISuite 4.0 (2009) estimates the Henry's Law constant by two different methods, resulting in two separate estimates. The methods are the Bond Contribution Method and the Group Contribution Method. The Bond Contribution Method estimates the Henry's Law constant based on the bonds present in the molecule, and a model developed using a training set of 263 substances. The Group Contribution method estimates the Henry's Law constant based on groups present in the molecule, and a model developed using a training set of 212 substances.

GLP compliance:

no

Remarks:

not applicable

H:

85 924 Pa m³/mol

Temp.:

25 °C

Atm. press.:

1 013 hPa

Remarks on result:

other: Group contribution method

H:

98 184 Pa m³/mol

Temp.:

25 °C

Atm. press.:

1 013 hPa

Remarks on result:

other: Bond contribution method

Conclusions:

The predicted Henry's Law Constant of the constituent is 85,924 Pa.m3/mole (Group method).

Executive summary:

The Henry's Law Constant of Butane has been predicted in EPISUITE v4.11 using the HENRYWIN model. The predicted Henry's Law Constant of the constituent is 85,924 (Group method) and 98,184 (Bond Method) Pa.m3/mole, respectively.

Reference 2

Endpoint:

Henry's law constant

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Estimated by calculation following the method as set out in the technical guidance document.

Justification for type of information:

The value has been calculated based on the physico-chemical characteristics of the substance and the equation set out in the Guidance Document Chapter R16 (ECHA 2012).

Principles of method if other than guideline:

Henry's Law Constant equation: (vapour pressure (Pa) * molecular weight (g/mol))/(water solubility (g/L) * 1000)

GLP compliance:

no

Remarks:

Not applicable

H:

15 972

Remarks on result:

other: Standard temperature and pressure assumed.

Conclusions:

The calculated Henry's Law Constant for 1,3-butadiene is 15972 Pa.m3/mol.

Executive summary:

The calculated Henry's Law Constant for 1,3 -butadiene is 15972 Pa.m3/mol. The value has been calculated based on the physico-chemical characteristics of the substance and the equation set out in the Guidance Document Chapter R16 (ECHA 2012).

Reference 3

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: QSAR calculation, acceptable with restrictions

Justification for type of information:

Two QSAR methods recommended by ECHA (2008) Guidance on information requirements and chemical safety assessment R7a Endpoint specific guidance.

Principles of method if other than guideline:

HENRYWIN v3.2 in EPISuite 4.0 (2009) estimates the Henry's Law constant by two different methods, resulting in two separate estimates. The methods are the Bond Contribution Method and the Group Contribution Method. The Bond Contribution Method estimates the Henry's Law constant based on the bonds present in the molecule, and a model developed using a training set of 263 substances. The Group Contribution method estimates the Henry's Law constant based on groups present in the molecule,and a model developed using a training set of 212 substances.

GLP compliance:

no

Remarks:

not applicable

H:

7 143 Pa m³/mol

Temp.:

25 °C

Atm. press.:

1 atm

Remarks on result:

other: Group contribution method

H:

7 893 Pa m³/mol

Temp.:

25 °C

Atm. press.:

1 atm

Remarks on result:

other: Bond contribution method

Conclusions:

The predicted Henry's Law Constant of the constituent is 7,143 Pa.m3/mole (Group method).

Executive summary:

The Henry's Law Constant of Buta-1,3 -diene has been predicted in EPISUITE v4.11 using the HENRYWIN model. The predicted Henry's Law Constant of the constituent is 7,143 Pa.m3/mole (Group method).

Description of key information

The members of this category are gases at standard temperature and pressure and will predominantly partition to the atmosphere. The use of QSAR to predict the Henry's Law Constant of representative constituents of these streams is an appropriate technique.

 

The representative constituents of the category studied and used as supporting read-across are But-1-en-3-yne (CAS 689-97-4), But-1-ene (CAS 106-98-9), But-2-ene, cis- (CAS 590-18-1), But-2-ene, trans- (CAS 624-64-6), Buta-1,2-diene (CAS 590-19-2), Buta-1,3-diene (CAS 106-99-0), Butane (CAS 106-97-8), Prop-1-ene, 2-methyl- (CAS 115-11-7), Propane, 2-methyl- (CAS 75-28-5).

 

The Henry's Law Constant has been taken from a QSAR prediction. The values of representative constituents were determined using the group and bond contribution methods. Henry's Law Constants were predicted to range from 7,143 to 103,352 and from 1,956 to 98,184 Pa.m3/mole for the group and bond contribution methods, respectively.