Combustible Dust Standard
The (OSHA) expects to publish before the end of the year a combustible dust standard, which the (CSB) has been calling for again in recent months.
OSHA had been expected to issue a standard in the first half of 2014, but it missed that deadline. But according to its schedule for the remainder of the year, OSHA now expects to deliver a standard under the Small Business Regulatory Enforcement Fairness Act in December.
The CSB has been calling for this standard since 2006. More recently, CSB chairman Rafael Moure-Eraso called for the standard in July after the publication of a final report into the .
The ALS facility milled and processed scrap titanium and zirconium into dense disks called 鈥渃ompacts.鈥� A fatal explosion at the plant seems to have started after sparks from metal-to-metal contact ignited metal powder in a faulty metal blender used to process zirconium. The CSB has created a to show how the accident may have unfolded.
After the release of that case study, Mr Moure-Eraso said the CSB 鈥渂elieves it is imperative for OSHA to issue a comprehensive combustible dust standard for general industry with clear control requirements to prevent dust fires and explosions.鈥�
, 鈥淢ost solid organic materials, as well as many metals, will explode if the particles are small enough, and they are dispersed in a sufficient concentration within a confined area, near an ignition source.鈥�
And he cautioned that even 鈥渟eemingly small amounts of accumulated combustible dust can cause catastrophic damage.鈥�
In , the CSB notes that accumulated dust of about 1/32nd of an inch, or the thickness of a dime, covering 5% of a room area is enough to fuel a 鈥渃atastrophic explosion.鈥�
A wide variety of materials that can be :
- Food (e.g., candy, sugar, spice, starch, flour, feed)
- Grain
- Tobacco
- Plastics
- Wood
- Paper
- Pulp
- Rubber
- Furniture
- Textiles
- Pesticides
- Pharmaceuticals
- Dyes
- Coal
- Metals (eg, aluminum, chromium, iron, magnesium, and zinc)
- Fossil fuel power generation, such as coal-fired power plant
And five things need to come together for there to be a dust explosion:
- Combustible Dust (Fuel)
- Oxygen (Air)
- Ignition Source (eg, electrostatic discharge, electric current arc, glowing ember, hot surface, welding slag, frictional heat or flame)
- Dust Suspension in air exceeding the minimum explosive concentration (MEC)
- Confinement (eg, vessel, room, building, ductwork)
Mr Moure-Eraso鈥檚 called again for the combustible dust standard in an August in the New York Times, in which he described dust explosions as 鈥渞eadily preventable with engineering controls, ventilation, training and other measures.鈥�
He recommended that voluntary, industry-supported national fire codes be codified and enforced through federal regulations.
Those codes include the 鈥檚 recommendations that companies:
- Control fugitive dust emissions;
- Design Facilities to prevent dust from migrating and accumulating; and
- Perform rigorous housekeeping to remove any dust that does build up.
Responding to the CSB鈥檚 calls for action in this area, an OSHA spokesman told in early September, 鈥淲e are continuing our efforts to move forward on combustible dust rulemaking, and OSHA has also put special emphasis on controlling combustible dust hazards through a national emphasis program, education and outreach.鈥�
OSHA says it will use the information gathered from (NEP) in 2008 to produce the standard now expected in December.