OSHA Underground: Upside Down Combustible Dust Bill

[Omaha Steve]

http://oshaunderground.blogspot.com/2009/02/upside-down-combustible-dust-bill.html

Saturday, February 7, 2009

Dust explosions garnered national attention this week with the catastrophic coal dust explosion at a Wisconsin coal-fired electrical energy plant in conjunction with the reintroduction of the combustible dust bill. While it is undisputed that worker protection is needed concerning combustible particulate solids that generate combustible dust in the manufacturing, non-manufacturing, and grain sectors. A question arises in the protective measures outlined in H.R. 849, “The Worker Protection Against Combustible Dust Explosions and Fires Act,” requiring the U.S. Occupational Safety and Health Administration (OSHA) to issue rules regulating combustible industrial dusts.

Stakeholders throughout the industrial sectors including the public must realize that dust explosions can never be totally prevented unless we completely shut down our manufacturing base and turn into a service based economy. For instance, we can learn from our New Zealand trading partner, where proactive dust explosion control measures are in place in protecting local and export industries.

Since instituting these control measures the amount of dust explosions have been constant as previously occurred without control measures. The only difference is the severity of these incidents have been reduced with measures like explosion venting and deflagration suppression best engineering practices.

Propagating Explosions
Combustible dust explosions follow under the subheading of propagating explosions quite similar to vapor cloud explosions in the refinery and petrochemicals sector where a combustion zone propagates at subsonic speeds wrecking havoc with the damaging effects of overpressure, thermal radiation, and ensuing projectiles. In March 2005, the catastrophic BP Texas City Refinery explosion is an example of a propagating vapor cloud explosion with similar damaging effects like the Imperial Sugar Refinery propagating dust explosion in February 2008.

Developing worker protection legislation in regards to combustible dust explosions as written in the current reintroduced bill fails to take into account many important aspects in providing basic layers of protection for the nation’s workforce. Additionally, solely utilizing the Chemical Safety Boards (CSB) recommendations as a template for the bill without taking into account many other life saving aspects of protection will not fully solve the problem of future incidents.

A good example is the recent catastrophic We Energies coal dust explosion that utilized national consensus National Fire Protection Association (NFPA) combustible dust standards as stipulated in the combustible dust bill, while implementing explosion control measures such as explosion ventilation panels that reduced the severity of the explosion. NFPA combustible dust standards provide excellent guidance in preventing and managing combustible dust fires and explosions but only to a certain level.

FULL story at link.

[hedgehog]

1. I question one statement on the link:

"Stakeholders throughout the industrial sectors including the public must realize that dust explosions can never be totally prevented unless we completely shut down our manufacturing base and turn into a service based economy."


Seems to me that dust explosions are prevented by keeping the dust out of the air and by removing ignition sources. Designing structures to vent when exposed to explosive pressures is a back-up.