Phosphorus

Stability: thermal, sunlight, metals

Administrative data

Endpoint:

stability: thermal, sunlight, metals, other

Remarks:

Migrated from section 'Stability: thermal, sunlight, metals'

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The data in this handbook are peer-reviewed and only published after a serious judgement by the authors. The slight restriction regarding the reliability is caused by unknown origin of the sample and the incompliance with GLP condition. Nevertheless the data are supposed to be representative also for untreated red phosphorus of the applicant.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

review article or handbook

Title:

Unnamed

Year:

1964

Materials and methods

Principles of method if other than guideline:

measuremet of the vapour pressure of the red phosphorus. This peer-reviewed article in the handbooks rely on several measurements and just mentioning the static method

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Phosphorus

EC Number:

231-768-7

EC Name:

Phosphorus

Cas Number:

7723-14-0

IUPAC Name:

phosphine

Details on test material:

This peer-reviewed article in the handbooks rely on several measurements without mentioning the origin of each sample of red phosphorus.
The data in the below mentioned table refer to a sample of red phosphorus which was prepared out of a liquid phosphorus at 280°C. One part of the samples was tempered for 720 hours at 550°C leading to a more crystalline structure whereby the other part remains untreated in the amorphous structure.

Results and discussion

For thermal stability study

Test substance thermally stable:

ambiguous

Sublimation:

yes

Transformation products:

yes

Identity of transformation products

No.:

#1

Reference

Reference substance name:

Unnamed

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 601-810-2]

CAS number:

12185-10-3

Molecular formula:

P4

Molecular weight:

ca. 123.895

For study on stability to sunlight

Test substance stable to sunlight:

not determined

For study on stability to metals

Test substance stable to metals / metal ions:

not determined

Applicant's summary and conclusion

Conclusions:

Red phosphorus decompose at very high temperature into gaseous white phosphorus, consisting of P4 molecules. It is stable up to a temperature of about 300°C. On further heating the vapor pressure slowly increases reaching 0.15 bar at 320°C. Between 400 and 420°C the vapor pressure of red phosphorus reaches 1 bar. The transition into the liquid state occurs between 579° and 625°C, at a corresponding pressure of approximately 42 bars.

Executive summary:

The vapour pressure of the red phosphorus depends form the molecular structure of the red phosphorus and is caused by the decomposition into gaseous white phosphorus, consisting of P4 molecules. Heating of red phosphorus in an inert atmosphere causes no significant changes up to a temperature of about 300°C. On further heating the vapor pressure slowly increases by the formation of gaseous white phosphorus, consisting of P4 molecules reaching 0.15 bar at 320°C. Between 400 and 420°C the vapor pressure of red phosphorus reaches 1 bar. The transition into the liquid state occurs between 579° and 625°C, at a corresponding pressure of approximately 42 bars.