A CSB investigation finding mentions that iron powder combustion lead to a fatality and injured another. The atomized iron powder dust dislodged during inspection by maintenance workers caught fire. Though, we know dust explosions, like ammonia fires/explosions, iron powder fire also is difficult to digest. Such information should be brought to the notice of all employees so that they will not be lax on their part.
Dust explosions are said to be more dangerous than normal explosions, as initiation of dust explosion can disturb the settled powder making it airborne and lead to secondary and tertiary explosions.
CSB mentions that metal powder dust flash fires and explosions cause more serious injuries than flammable gas or vapor fires because of radiant heat. A CSB study on 281 combustible dust fires and explosions during 1980-2005 indicate 119 deaths and more than 700 injuries due to these incidents.
The best way to avoid dust explosions is to have dust collections systems, regular wet mopping, flameproof electrical fittings, maintaining atleast 50% humidity, static charge discharge mechanisms, etc and maintaining records to ensure that safety systems are maintained.
A news item on the above is also available here(1), here (2) and here(3) , here(4)..