Tuesday, February 22, 2011

Hot Work Safety - Hot Work Requirements and Combustible Dusts - Safety Engineering Network (SAFTENG)

From SAFTENG the Safety Engineering Network, this blog post brings up some good questions.  This is one area of major concern, as several of the fires that caused massive amounts of damage in facilities that create or process combustible dust were started by contractors welding on a duct, dust collector or vessel, or near these areas where combustible dust had built up.

Hot Work Safety - Hot Work Requirements and Combustible Dusts - Safety Engineering Network (SAFTENG)

OSHA has clearly established that hotwork can not take place in the presence of combustible dusts. 1910.252(a)(2)(vi) Prohibited areas. Cutting or welding shall not be permitted in the following situations:

1910.252(a)(2)(vi)(A) In areas not authorized by management.
1910.252(a)(2)(vi)(B) In sprinklered buildings while such protection is impaired.
1910.252(a)(2)(vi)(C) In the presence of explosive atmospheres (mixtures of flammable gases, vapors, liquids, or dusts with air), or explosive atmospheres that may develop inside uncleaned or improperly prepared tanks or equipment which have previously contained such materials, or that may develop in areas with an accumulation of combustible dusts.

The area of concern that I wish to bring to light is doing hotwork in areas where the combustible dust is either a ways below you or above you. If you are in a large industrial complex that spans many floors, and lets say you are working on the first floor. The area is a combustible dust area, even rated as a Class 2 Div 2 HAZLOC. Your housekeeping program does a good job of cleaning at ground level, but not such a good job on those areas not accessible from the ground. Some of those beams can have 1" layer of combustible dust on them and span 35' across with four beams per floor and 10 floors above you.

Do we make any attempt to clean this dusts?
How high do we clean so as to remove the threat of the dust falling on the hotwork?


Monday, February 21, 2011

Risk Factors: Combustible Dust Standards Update

From Risk Factors blog and WestField Insurance, here is a good overview of the current state of the OSHA Combustible Dust Standard, with related links.

February 16, 2011

Risk Factors: Combustible Dust Standards Update

Combustible dust has become a much more visible hazard in the past few years as the Occupational Safety & Health Administration (OSHA) in 2008 communicated that they were proposing a new standard on combustible dust. They also set in play a new directive for their staff to step up their inspections of plants that produce combustible dust, and began forcing companies to control the risk of explosion/fire (and related health concerns) through the execution of the general duty clauseusing best practice industry consensus standards (mostly National Fire Protection Association (NFPA) standards).

The concern was that in the past couple decades, multiple industries experienced dust explosions that resulted in the loss of life/injuries and major property damage. As a result of several high-profile incidents, in 2006 the Chemical Safety Board (CSB) published their Combustible Dust Hazard Study which reported that from 1980 through 2005, combustible dusts caused 281 incidents that killed 119 workers and injured 718. Between 2006 & 2008, an additional 16 deaths and 84 injuries occurred. Finally, in February 2008, the high-profile explosion(s)/fire at the Imperial Sugar refinery (Port Wentworth, GA) resulted in 14 fatalities and 42 injuries. This was the proverbial “last straw” for OSHA to take action.

Current Status
Almost exactly one year ago today (Feb 17, 2010), OSHA closed their public comments on their “approach” to use in developing their federal standard for combustible dust and hosted a Combustible Dust Stakeholder Meeting in Atlanta, GA to gather additional feedback from stakeholders before they started developing the standard in full force. On April 13, 2010, they published a summary report of the meeting (see

Currently, OSHA continues work on this standard. In a “web chat” a couple days ago (2/14/11), Secretary of Labor Hilda Solis noted that the budget proposed by the Obama Administration calls for a $37 million dollar increase in funding for OSHA’s Standards Group. The development of the combustible dust standard is one of just a handful of priorities mentioned- so it is likely a measure of time until a standard is forthcoming.

Nature of Combustible Dust Hazards & Controls
Rather than go into detail here, OSHA has put together a comprehensive overview (in layman’s terms) of the hazards and necessary controls to consider at
Other helpful related OSHA web links include:
- (applicable standards)
-  (Combustible Dust National Emphasis Program)

National Fire Protection Association (NFPA)
The National Fire Protection Association (NFPA) is a national organization that promotes and publishes fire and life safety consensus standards. They are not the only organization that publishes standards, but are the most well known and widely accepted organization in the United States (and much of the world for that matter). The primary standard that applies to combustible dust is NFPA 654: Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids. This standard was first published in 1975 and has undergone six revisions, with the newest revision scheduled to be adopted/published in late 2012 (originally in 2011 but was purposely delayed). Under the new edition, look for the following changes from the most recent (2006) edition:
-   Expansion of the definition of combustible particulate since most combustible solids that are broken down into a finely divided solid form can contribute to a deflagration.
-   Implementation of a planned inspection process to determine facility dust accumulation rates and determine housekeeping actions/frequency necessary to maintain accumulations below acceptable levels.
-   Recommended cleaning methods: Such as vacuuming rather than blowing down- which can create more hazardous conditions than simply doing nothing.
-   New/expanded sections on hazard assessment, ignition hazards, and contractors to name a few.

NFPA also publishes the following more specific standards relative to combustible dust (which all reference NFPA 654):
-          NFPA 664: Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities
-          NFPA 61: Standard for the Prevention of Fires and Explosions in Agricultural and Food Processing Facilities
-          NFPA 484: Standard for Combustible Metals
-          NFPA 655: Standard for Prevention of Sulfur Fires and Explosions
 These standards refer to a host of other NFPA standards (e.g. NFPA 70 National Electric Code) and can get quite complicated, so competent professional guidance is a must.

FM Global
FM Global (formerly Factory Mutual Insurance Co.) self-publishes Data Sheets that identify hazards and recommended controls based on both industry consensus data as well as their own research data. The company is well-known for its conservative approach to controlling property hazards. FM Global publishes Data Sheet 7-76 Prevention And Mitigation Of Combustible Dust Explosion And Fire as well as several related standards in addition to “approving” equipment that can be used for specific (e.g. dust) environments. FM Global used to charge for this information; however, they no longer do so as long as you register (for marketing/informational purposes). The website where these data sheets can be found is

Jeff Hendershot is a Property Specialist with Westfield Group. You can connect with him at

Thursday, February 17, 2011

Interactive Combustible Dust Guide

In The News: Interactive Combustible Dust Guide Now Available

The Dust Task Force of the Wood Machinery Manufacturers of America (WMMA) recently released the "WMMA NFPA 664 Interactive ComDust Guide" to help simplify the requirements set out by the National Fire Protection Association (NFPA). "NFPA has issued several standards and it can be quite difficult to get a good overview of these standards," according to a release issued by WMMA. "It is important for the user to understand that in each case the user must consult the applicable standard to assure the particular facility/process being assessed complies with the correct standard."