The oxygen concentration in a slightly rusted tank with traces of salt and in high humid conditions, may go down to next to nothing in 24 hours or less. Therefore always take an oxygen reading before entering a tank even though a reading had been taken a few hours beforehand. The materials in many tanks are blanketed with nitrogen gas. A person opening the tank hatch could lose consciousness due to lack of oxygen and fall inside the tank. Defective wiring in a wet atmosphere may electrocute an employee.
Dust explosions are well known to occur in grain silos.
Grain may also agglomerate and form a bridge or dome across a bin. This grain may fall and entrap or suffocate a grain worker. An employee may be injured while working inside a silo if an auger or other piece of equipment is turned on. A permit, pre-authorized entry plan, written records of steps followed and approved training may be required 2. Ensure safe access and egress.