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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Stability: thermal, sunlight, metals

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
thermal stability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012-07-06 to 2012-08-15
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study is regarded as reliable without restrictions because it was conducted in compliance with GLP regulation and guideline.
Qualifier:
according to guideline
Guideline:
OECD Guideline 113 (Screening Test for Thermal Stability and Stability in Air)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test substance thermally stable:
yes
Operating temp.:
>= 30 - <= 68 °C
Remarks on result:
other: All test showed an endothermic event (melting) with an mean onset temperature of 68 °C and an exothermal event (decomposition) starting at 150 °C and lasting over a wide temperature range up to approximately 300 °C.
Sublimation:
no
Test substance stable to sunlight:
not determined
Test substance stable to metals / metal ions:
not determined

In the table below the recorded data of all measurements are summarized.

Event

No.

Heat flow

Exothermic events

Test 1

Test 2

Test 3

1

endothermal

Onset [°C]

68.3

68.4

66.1

2

exothermal

Onset [°C]

150

150

150

Peak Maximum [°C]

212

213.6

211

Int. norm. [J/g]

810

409

715.5

 

 

Loss in weight [mg]

0.0

15.7

0.0

 

 

Loss in weight [%]

0

85

0

 

All test showed an endothermic event (melting) with an mean onset temperature of 68 °C and an exothermal event (decomposition) starting at 150 °C and lasting over a wide temperature range up to approximately 300 °C. Experiment 2 was performed with an open crucible at ambient atmosphere. At this test a significant loss of mass was found.

Conclusions:
The test item is classified to be thermally stable at room temperature.

Description of key information

In a thermal stability study, no exothermal event was observed below the decomposition temperature. Therefore the test item 4-Hydroxy TEMPO is classified to be thermally stable at room temperature. 

Additional information

The thermal stability of 4-Hydroxy TEMPO was determined according to the OECD TG 113. Samples of the test item were weighed into glass crucibles. All samples were exposed to a temperature/time-gradient while the thermal heat-flow was recorded. All tests showed an endothermic event (melting) with an mean onset temperature of 68 °C and an exothermal event (decomposition) starting at 150 °C and lasting over a wide temperature range up to approximately 300 °C. According to the OECD Guideline 113 an exothermic event is assumed to be a decomposition. None of the results showed an exothermal event starting below 150 °C. Therefore the test item 4-Hydroxy TEMPO is classified to be thermally stable at room temperature.

Justification for classification or non-classification

Based on the study results, the substance was considered to be thermally stable at room temperature. No classification with regard to thermal stability according to Directive 67/548/EEC (DSD) and Regulation (EC) No 1272/2008 (CLP) is required.