Hop, Humulus lupulus, ext.

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 September 2017 - 04 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

The testing laboratory is GLP compliant and the test was carried out according to the principles of GLP. An internal standard operating procedure was followed for the direct scanning calorimetry tests.

Principles of method if other than guideline:

Date 02/10/2017
SOP Reference CTL SOP 320
Test System DSC System 1
Test Filename DSC4028001957A
Crucible Type Gold-lined steel (high pressure, sealed)
Sample Preparation Tested as received
Start Temperature -40°C
Trip Temperature 400°C
Ramp Rate 4 K.min-1
Test Atmosphere Air
Sample Mass 4.7 mg

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

Hop extract - CO2 extract of Humulus lupulus variety 'Cascade'. Batch number 160025. Principal components: alpha acids: 35.06% w/w; beta acids: 38.47% w/w; essential oils: 8.92% v/w

Key result

Remarks on result:

not determinable

Remarks:

No firm boiling point noted on DSC, as expected for a plant-derived UVCB material. Exotherm events show different components degrading, but no clear boiling point. The material decomposes before boiling.

Notes from the test report: "The sample was observed to undergo an exothermic event from 60.3°C which had a heat of decomposition of -24.7 J.g-1. A second exothermic event was then observed to commence from 138.0°C which had a heat of decomposition of -157.7 J.g-1. No further significant energetic events were noted up to 400°C."

The DSC plot is attached - see "Illustration (picture/graph)"

Conclusions:

Substance decomposes before boiling.

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

400 °C

Additional information

No clear boiling point was noted. This is as expected for a plant derived UVCB. The exotherm events on the DSC trace show various components degrading, but there is no observable boiling point. The substance decomposes before boiling. Upper temperature tested (400^oC) used for CSR.