Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

2,4,6-trimethyl-1,3,5-trioxane

2,4,6-trimethyl-1,3,5-trioxane is colorless, transparent liquid with a characteristic aromatic odor.

CAS 123-63-7 Warning

01 · Identification

What 2,4,6-trimethyl-1,3,5-trioxane is

2,4,6-trimethyl-1,3,5-trioxane is colorless, transparent liquid with a characteristic aromatic odor. It boils at 125 °C, melts at 12.6 °C.

Under the GHS it carries the signal word Warning. It is classed as flammable agents - 3rd degree.

CAS number123-63-7
EC number204-639-8
Index number605-004-00-1
Chemical class Flammable agents - 3rd degree

Other names for 2,4,6-trimethyl-1,3,5-trioxane

  • paraldehyde

02 · GHS classification

Hazards and label elements

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Signal wordWarning
Hazard statements assigned to 2,4,6-trimethyl-1,3,5-trioxane
CodeHazard statement
H226 Flammable liquid and vapour.

Precautionary statements: P210, P233, P241, P242, P403

03 · Physical and chemical properties

2,4,6-trimethyl-1,3,5-trioxane properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Property Value Conditions Source
Boiling point 124.5 °C (256.1 °F) HSDB
127.78 °C (262 °F) at 760 mmHg CAMEO
Melting point 12.6 °C (54.7 °F) HSDB
12.61 °C (54.7 °F) CAMEO
Density 0.9923 g/cm³ at 20 °C HSDB
0.991 g/cm³ at 20 °C HSDB
0.9943 g/cm³ at 20 °C CAMEO
Solubility Sol in water: 1 in 9 parts at 20 °C, 1 in 10 parts at 30 °C, & 1 in 11.5 parts at 37 °C at 20 °C HSDB
Sol in sodium chloride solution: 1 in 9.5 parts at 20 °C, 1 in 11 parts at 30 °C, & 1 in 12.5 parts at 37 °C at 20 °C HSDB
SOL IN 8 PARTS WATER AT 25 °C; 17 PARTS BOILING WATER at 25 °C HSDB
Vapor pressure 25.3 mmHg at 20 °C HSDB
7.5006 mmHg at 20 °C ICSC
7.5 mmHg at 17 °C DOE PAC
Flash point 35.56 °C (96 °F) HSDB
24 °C (75.2 °F) ICSC
Autoignition temperature 237.78 °C (460 °F) HSDB
235 °C (455 °F) ICSC
Lower explosive limit (LEL) 1.3 % by volume HSDB
Upper explosive limit (UEL) 17 % by volume ICSC
Vapor density 4.5 (air = 1) HSDB
Odor threshold 0.02-0.025 mg/cu m (recognition) HSDB
Critical temperature and pressure 290 °C (554 °F) HSDB
Corrosivity ... Has solvent action upon rubber, polystyrene, & styrene-acrylonitrile copolymer like HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling 2,4,6-trimethyl-1,3,5-trioxane

Storage conditions

PARALDEHYDE SHOULD BE STORED IN WELL-FILLED, TIGHT, LIGHT-RESISTANT GLASS CONTAINERS WITH A CAPACITY OF NO MORE THAN 30 ML, AT A TEMP NOT EXCEEDING 25 °C.

Source: Hazardous Substances Data Bank (HSDB)

Incompatible materials

Paraldehyde is incompatible with many plastics

Source: Hazardous Substances Data Bank (HSDB)

Reactivity

PARALDEHYDE is an ether derivative. This compound is decomposed by light and air, on prolonged storage, to acetaldehyde and acetic acid. Incompatible with alkalis, hydrocyanic acid iodides and oxidizers. (NTP, 1992)

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check 2,4,6-trimethyl-1,3,5-tri… in the storage compatibility matrix →

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