Chemical Properties
light yellow crystal(s) [HAW93]
General Description
Light-yellow crystals, light-gray powder, or fused solid. Melting point 310°C. Density 2.19 g / cm3. May spontaneously heat and ignite under exposure to moisture. Produces phosphorus pentaoxide and sulfur dioxide during combustion. Phosphorus pentaoxide reacts with water to form phosphoric acid, a corrosive material. Phosphorus heptasulfide reacts with water to form phosphoric acid and hydrogen sulfide, a toxic flammable gas with a rotten-egg smell. Continued exposure to hydrogen sulfide disables the sense of smell.
Air & Water Reactions
Highly flammable.Reacts with liquid water or atmospheric moisture to form toxic hydrogen sulfide gas and corrosive phosphoric acid.
Reactivity Profile
PHOSPHORUS HEPTASULFIDE is a reducing agent. Can react vigorously with oxidizing agents including inorganic oxoacids, organic peroxides and epoxides. Simple salts of sulfides (such as sodium, potassium, and ammonium sulfide) react vigorously with acids to release hydrogen sulfide gas.
Health Hazard
Highly toxic: contact with water produces toxic gas, may be fatal if inhaled. Inhalation or contact with vapors, substance or decomposition products may cause severe injury or death. May produce corrosive solutions on contact with water. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
Fire Hazard
Produce flammable and toxic gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Containers may explode when heated. Runoff may create fire or explosion hazard.
Safety Profile
A poison by ingestion. Flammable when exposed to heat or flame; can react vigorously with oxidizing materials. When heated to decomposition it emits very toxic fumes of POx and SOx. See also SULFIDES and PHOSPHORUS
