Dust Explosion

Reason why Hazard related to Dust Explosion is get ignored or learning from past incident is still not implemented in most industries are summarized as following:

1. “Many plants are still in the complacent mindset, where they have never experienced a major event and hence feel their risk is not high enough to worry about.”

2. “Complacent mindset of being low risk purely based on no significant event history.

3. “The common thinking is, ‘It never happened before, that costs too much money, we don’t have a problem, etc.,’ are often the challenges in a growing climate of risk acceptance.”

4. “Growing climate of risk acceptance, the challenge isn’t getting new ideas in one’s head, but rather getting old thoughts out of one’s head.” [26]

5. “Dust fires in the workplace are quite common, but most of the time people say, ‘Oh this has always happened,’ and ‘it’s never resulted in an explosion before’, so it does unfortunately result in a sense of complacency.

6. “People don’t realize that all that’s required is confinement for a dust explosion to occur under those conditions.”

7. “If certain facilities are used to frequent fires, but have never had an explosion, the natural tendency is to believe that there would have been an explosion by now if one were going to happen.”

Managing causal attribution is a keyway to minimize the normalization of risk.

However, incident investigation related to dust explosion indicated that dust control was seen as a significant cost to production:

• “Safety is a non-event, think of it as a control loop with a much-delayed feedback signal, then the control loop starts to drift. Production is tangible and can take priority over safety.”
• “One of the biggest issues is the attitude of, ‘we’ve been operating for __ and we have never had an issue so why do we have to spend all this money on stuff that isn’t going to happen here?’”
• “Some customers fear that once they start understanding the issue that they will need to comply fully, and the cost will be too high to sustain a competitive position in the industry.”
• “Balance cost of doing everything they can to reduce risks and reducing risks as much as their budget will allow.”
• “Safety choices are based on fear of efficiency, not fear of danger and incidents.”

Control Measures:

1. Elimination: Most respondent to the Call to Action felt that there was no way to completely eliminate the hazard of combustible dust. "You can't eliminate all dust - reduce it to keep the chances of an incident low". Investigation also suggest that it was "hard to remove fugitive dust - industries default to "remove ignition source". "The workplace can fall anywhere in continuum of dusty vs. safe. “Note that a large fraction of dust explosions that occur do so in dust collectors and those that are processing fines of the fines. If possible, these need to be located outdoors, away from people and property.”
2. Substitution: Findings suggests that dust to be an inevitable biproduct of production. This was often coupled with comments regarding the variability of dust explosivity and amount if dust, which is often related to change.
3. Engineering Control: From past learning these are believed to be effective and are core in the current NFPA recommended practices. Due to normal system and human variability, these mitigation strategies literally ‘work until they don’t’.
4. Administrative and PPE: Administrative controls and PPE are frequently used with existing processes where hazards are not particularly well controlled. Administrative controls and PPE programs may be relatively inexpensive to establish but, over the long term, can be very costly to sustain. These methods for protecting workers have also proven to be less effective than other measures, requiring significant effort by the affected workers. - Intervention required

Regulatory Compliance:

1. OSHA and The National Grain and Feed association (NFGA) cocreated a grain handling standard in 1988, which resulted in fewer fire and explosion related fatalities since the rule was promulgated.
2. Bill Wright, interim chair of the U.S. Chemical Safety and Hazard Investigation Board (CSB), testified during the House Education and Labor committee’s March 12, 2008 hearing on H.R.5522 – the ‘Combustible Dust Explosion and Fire Prevention Act of 2008’ – that the frequency of grain facility explosions declined by 60 percent following implementation of the grain-handling standard.
3. The newest, NFPA 652: Standard on the Fundamentals of Combustible Dust, became effective on Sept. 7, 2015.
4. NFPA 654: Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids, contains requirements for PHAs that include dust hazard assessments (DHAs).

Conclusion and Recommendations:

Sharing information was found to be the most desired and valued topic from respondents.

1. Outcomes from past indicated key areas of systemic improvement that could reduce the likelihood of future dust explosions.
2. Create a ‘living risk’ document that is updated as the system changes, to supplement the DHA.
3. Explore what can be learned from industries that report success with dust hazard education and mitigation.
4. Develop standards to certify dust collection system manufacturers, installation and training.
5. Develop combustible dust procedures that are distinct from ‘housekeeping’ and unique to each facility’s manufacturing variability. Present dust as a unique hazard, not just as ‘tidying up the place’.
6. Explore how common terms and language may adversely influence the awareness of hazards.
7. Identify and mitigate language barriers that exist within facilities.
8. Create psychological safety in organizations to facilitate the willingness of personnel to provide information and ask questions.
9. Recognize that training does not always lead to learning. Develop experiential and collaborative learning methods to help all personnel understand combustible dust risks and mitigation strategies.
10. Share learning and experience within a company, industry and across industries.