A colorless to yellow to red oil, fuming and with a choking odor
Molecular Formula	SOCl2	Molecular Weight	118.98
Boiling Point	76°C	Melting Point	-104.5°C
Vapor Density	4.1	Liquid Density	1.638
Vapor pressure	16 kPa at 25°C
Not flammable

Also refer to 2000 Emergency Response Guidebook (ERG2000) Guide 137.

Health Hazards

Thionyl chloride is decribed as corrosive. It reacts with water with the release of hydrochloric acid and sulfur dioxide. It can be irritating to mucous membranes and can be damaging to the eyes, mouth, throat and lungs. Skin can be burned and inhalation can cause lung damage and pulmonary edema, which can be fatal. In some cases, ill efects from exposure have been delayed for several hours after exposure. Environmental exposure limits are generally set at 1 ppm (5 mg.m^-3) for 15 min.

Risk and Safety Phrases.

INDUSTRIAL/COMMERCIAL USES

Thionyl chloride is a versatile and effective chlorinating agent that can be used in a number of industrial chemical reactions. Despite the health hazards, thionyl chloride is easier to handle than other chlorinating agents and has the advantage of producing gaseous side products, which simplifies processing in industrial chemistry and also leads to high yields of products. The most important of these are the formation of the useful and highly reactive carboxylic acid chlorides, aromatic sulfochlorides and alkyl chlorides. Thionyl chloride also reacts with amines and sulfamic acids with the sulfamyl chloride reaction products from sulfamic acids being important intermediates in the synthesis of some herbicides. Thionyl chloride is also used as the electrolyte in high performance lithium-thionyl chloride batteries.

COMMENTS

Thionyl chloride is used in the "di-di" method of manufacturing G-type nerve agents. It is another precursor that can be made from very common or easily made precursors including chlorine and oxides of sulfur.It can also be made in reactions using one of two other listed precursors: sulfur monochloride or sulfur dichloride.