Sulfur differs from most combustible dust by having a relatively low ignition temperature. The ignition temperature of sulfur dust clouds varies upward from approximately 190ºC. Dilutions of sulfur with inert solids are not effective in raising the ignition temperature.
Whenever the handling of sulfur creates a dust cloud, an explosion is an ever-present possibility. Besides its low ignition temperature, a dust cloud can create a static electric charge among the air-suspended sulfur particles. The static discharge can readily cause ignition.
Sulfur dust explosions occur with very rapid discharge of flame and pressure waves. When confined or other-wise restricted in a building, pressure waves can cause a great deal of damage.
Sulfur reacts violently with strong oxidizing agents, such as nitrates and chlorates. It will also undergo chemical change at moderate rates with alkalis.
Sulfur should be stored in a dry area. When it is wet, sulfur reacts to form a very weak sulfuric acid. This can eventually deteriorate bags and most other items. Use skids to prevent contact between damp floors and bags carrying sulfur.
In addition, to reduce the chance of fire and explosion, only well ventilated areas should be used for storage. Storage area doors also should be made of non-combustible material and be the type that can be easily blown out with an explosion.
Ground sulfur is essentially non-toxic through skin contact, ingestion and inhalation. However, it can irritate the skin and eyes as well as the respiratory system.
Sulfur deposited on skin can be washed away with mild soap and water. Eyes that have come into contact with sulfur dust are to be flooded with water for at least 15 minutes. This must be thorough. An inadequate attempt may actually increase the inflammation.
Do not use a boric acid solution for eye washing. Sulfur dust is an acid irritant. Since boric acid is a weak acid, it will further inflame an already acid-irritated eye. For eye and respiratory protection, breathing apparatus and dust-tight goggles should be worn.