Product Identification
【Product Name】Pyridine sulfur trioxide
【Synonyms】吡啶三氧化硫
【CAS】26412-87-3
【Formula】C5H5NO3S
【Molecular Weight】159.16
【EINECS】247-683-3
【Beilstein/Gmelin】3704116
【Beilstein Reference】5-20-05-00184
【EC Class】harmful, irritant

Physical and Chemical Properties
【Appearance】White to beige powder.
【Solubility in water】Decomposition
【Melting Point】155-165℃
【Usage】Used as an activating electrophile in a swern like oxidation.

First Aid Measures
【Ingestion】If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
【Inhalation】Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
【Skin】Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
【Eyes】Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Handling and Storage
【Storage】Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from water.
【Handling】Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Avoid contact with eyes, skin, and clothing. Avoid ingestion and inhalation.

Hazards Identification
【Ingestion】May be harmful if swallowed. Causes digestive tract irritation.
【Inhalation】Causes respiratory tract irritation. Causes irritation of mucous membrane.
【Skin】Causes mild skin irritation.
【Eyes】Causes severe eye irritation.
【EC Risk Phrase】R 22 34
【EC Safety Phrase】S 26 36/37/39 45
【UN (DOT)】3261

Exposure Controls/Personal Protection
【Personal Protection】Eyes: Wear appropriate protective eyeglasses or chemical safety ggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
【Respirators】A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.

Fire Fighting Measures
【Autoignition】>350℃
【Fire Fighting】Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. To extinguish fire, use water spray, dry chemical, carbon dioxide, or alcohol-resistant foam.

Accidental Release Measures
【Small spills/leaks】Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal.

Stability and Reactivity
【Disposal Code】12
【Incompatibilities】Metals, strong oxidizing agents, moisture, diphenylmercury.
【Stability】Stable under normal temperatures and pressures.
【Decomposition】Nitrogen oxides, carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide, nitrogen.

Transport Information
【UN Number】3261
【HS Code】2942 00 00