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Physical & Chemical properties

Additional physico-chemical information

Administrative data

other: Differential Scanning Calorimetry
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Conducted at a GLP accredited laboratory.

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
other: Laboratory method
Principles of method if other than guideline:
Test Objective to clearly identify exothermic or endothermic activity in a reagent, reaction intermediate, reaction mass or final product and to provide some guidance as to the magnitude and onset of any such event.Test PrincipleA quantity of sample, normally 5 - 10 mg, is sealed in a test crucible. This is placed in a furnace cell along with an empty reference pan. The furnace is allowed to equilibrate to the starting temperature and both pans are then heated at between 0.5 and 20 K.min-1 until the final temperature is reached. The temperature of the sample and that of the reference pan are monitored. Any exothermic activity within the sample will result in a larger heat flow out of the cell relative to the reference pan. All data is logged using a microcomputer.Test SensitivityThe Differential Scanning Calorimeter has an approximate sensitivity of ca. 5 Test MethodThe test sample is charged to the test crucible which can be high pressure (sealed) gold construction or can be an open (or pierced lid) aluminium cell. An empty cell, used as a reference pan, is similarly prepared. The sample and reference pans are then placed into a furnace which is heated to 25°C. Once the pans have equilibrated with the furnace, the cells are heated at a constant rate (of up to 20 K.min-1) up to 500°C. Microcomputer data logging is used to monitor the power output of the sample and the temperature in the oven.Data InterpretationThe onset temperature is indicated by examining any deviation in the reaction mass temperature from the heating rate, the peak height or area under the curve indicating the magnitude of the energetic activity. It is imperative that safety factors are used when relating screening test data to large scale plant. Typical safety factors of up to 100°C are used on the first detected onset temperature, although this will be very dependant on thescale on which the material is to be handled and stored. If the material is to be stored or handled at a temperature near its' thermal threshold (including a safety factor), it is recommended that further tests are conducted under low heat loss conditions to more accurately quantify a safe maximum exposure temperature. The slow heating rate used in the DSC test produces a much more accurate definition of onset temperature than thatwhich would be obtained at higher heating rates, and may enable a reduction in the safety factor. However, when data gained at high heating rates (2 K.min-1 or higher) is interpreted, safety factors of up to 100°C are commonly used.
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
sodium (xylenes and 4-ethylbenzene)sulfonates
EC Number:
Cas Number:
Molecular formula:
sodium (xylenes and 4-ethylbenzene)sulfonates
Details on test material:
- Name of test material: sodium xylenesulphonate- Molecular formula: C8H9O3SNa- Molecular weight: 208.2- Physical state: solid- Analytical purity: not mentioned- Impurities: not mentioned- Composition of test material, percentage of components: 90%, saturated solution- Expiration date of the lot/batch: Dec 2010- Storage condition of test material: in original container protected from direct sunlight in a dry cool and well-ventilated area

Results and discussion

No significant energetic events were noted up to 500°C.

Any other information on results incl. tables

Test Procedure

A sample of Sodium Xylenesulphonate (6.5 mg) was charged to a gold (high pressure) DSC crucible which was then sealed and placed in the furnace. The sample was then ramped from 25°C to 500°C at 4 K.min-1.

Applicant's summary and conclusion

Executive summary:

No significant energetic events were noted up to 500°C.