In January 2004, an explosion at the West Pharmaceutical Company in Kingston, NC killed 6 workers and injured 34 others. Two firefighters were injured during the response to the incident.  One month later, an explosion and fire occurred at the CTA Acoustics manufacturing facility in Corbin, KY, killing 7 workers. In February 2008, an explosion at the Imperial Sugar Company facility in Wentworth, GA, killed 13 workers and injured 42 others. Three very different types of facilities with very different products, but with one thing in common—dust!

The Chemical Safety Board reported that there were 281 explosions of combustible dust in the United States between 1980 and 2005. These explosions resulted in 199 deaths and 718 injuries. And these are just the actual explosions. There are countless more combustible dust environments just waiting for the right (or wrong) conditions to align to become the next fatal explosion. The fact is that with the exception of silicon or sand, every kind of dust is potentially combustible to some degree.

Combustible dusts are measured on a “deflagration index,” (see box) which measures the relative explosion severity compared to other dusts. They range from such seemingly innocuous items such as dust from powdered milk and egg whites that can create “weak explosions,” to dusts from items such as magnesium and aluminum that can result in “very strong explosions.” But I think we can all agree that no explosion, even a “weak” explosion, is a good explosion—especially if it occurs during rescue operations. 

As rescuers, you should already be familiar with the “fire triangle.” To understand the danger of combustible dusts, you should also be familiar with the “dust explosion pentagon.” The dust explosion pentagon consists of the following:

-       Combustible Dust (Fuel)

-       Ignition Source

-       Oxygen

-       Dispersion of dust (suspension)

-       Containment of the dust in a confined or semi-confined area (Enclosures/Building/Confined Space)

Rescuers should be on the lookout for any appreciable accumulation of dust when sizing up a rescue situation. Keep in mind that your atmospheric monitor containing a sensor for combustible gases is not effective for detecting a hazard from combustible dust.  

Always remain aware that in a suspended state, dust becomes explosive. Dust explosions occur when combustible dust is present, forms a dust cloud in an enclosed environment, and is exposed to oxygen and an ignition source. The explosion occurs as a result of the rapid burning of the dust cloud, which creates a rapid pressure rise in the enclosed area or confined space. 

A dust pile that may burn while an ignition source is being applied, then go out immediately or shortly after the ignition source is removed, can become lethally explosive when scattered and suspended in the air. 

Always consider the potential for combustible dust in any rescue situation, particularly when ventilation of an enclosure, building, or confined space is considered. A “safe” area can become a ticking bomb if ventilation results in the suspension of otherwise stable dust accumulations.

This article was written by Robert Aguiluz, who is currently an Administrative Law Judge for the State of Louisiana. He is also an attorney who specializes in Occupational Safety and Health Law, and regulatory and compliance issues. He is a former Certified Safety Professional and Roco Rescue Instructor with over twenty years’ experience in both industrial and municipal emergency response and rescue.
 

Combustible Dust Considerations for Emergency Responders:

1.  Know your response area and the types of industry that may have the potential for combustible dust. If you are performing standby rescue duties, meet with the SH&E management team to learn about any combustible dust hazards at their facility.

2.  Become familiar with the “deflagration index” for various types of materials. See sample Chart below.

Examples of Kst Values for Different Types of Dust

3.  Consider the effect of ventilating a space that has accumulations of combustible dust.

        •  Will you cause the dust to become suspended?
        •  Will the suspended moving dust create a static charge/discharge and become a source of ignition?
        •  Can your ventilation equipment become a source of ignition?

4.  Is there information to review on the SDS (Safety Data Sheet) regarding the material’s potential to become combustible dust?

HELPFUL LINKS:

OSHA Quick Card: Prevent Dust Explosions

“Firefighting Precautions at Facilities with Combustible Dust”

“Hazardous Communication Guidance for Combustible Dust”

“Combustible Dust in Industry: Preventing and Mitigating the Effects of Fire and Explosions”

“NFPA 654: Standard for the Prevention of Fire and Dust Explosions”

OSHA's final rule on confined spaces in construction is being reviewed by the Office of Information and Regulatory Affairs. The review is one of the final steps required before OSHA can formally publish the rule.

OIRA, which is a branch of the White House's Office of Management and Budget, received the rule for review on Nov. 14. The office is limited to a 90-day review but can request an extension. The rule has been in the works since at least 2003; the proposed rule was published in 2007.

Several provisions in the proposed rule are similar to those found in the agency's confined spaces standard for general industry. That rule, issued in 1993, mandates specific procedures and includes requirements such as a written program, atmospheric monitoring and training.

Stand by for additional updates on this regulation.

News story from the National Safety Council. 

In a recent article in ASSE’s Professional Safety magazine, we found some very important points to consider for rescuers. Whether you are preparing for stand-by rescue operations, getting ready to enter an “abandoned in place” vessel, or just found the “perfect” retired vessel to use for your upcoming rescue training…proceed with caution!

The article does a great job of reminding us that not so long ago the emphasis on safety was far less than it is today. This becomes very clear when we compare current safety practices, such as Management of Change (MOC), and how the absence of that particular management tool has left many retired confined spaces and other systems in a potentially dangerous state.

Because of the potential dangers posed to emergency responders, we wanted to share this article with our readers.

Click to download the full article

Here are some key points from the article “Retired and Dangerous, Out-of-Service Equipment Hazards” by Robert Wasileski.

• Management of Change is emphasized more during the design and operational phase of equipment life cycles, but receives little emphasis when it is time to retire the equipment. 

• Older facilities have a high potential to have retired equipment that haven’t had all hazards addressed and may pose serious risks.

• Equipment that has been out of service for an extended period of time often has very little data on record stating how it was prepared to be taken out of service.

• There are many instances of chemical reactions that can change the physical condition of the equipment over time.  

The author provides several case studies that are truly enlightening. It includes some excellent lessons for rescuers when dealing with out-of-service or “moth-balled” vessels. While a couple of the cases delve pretty deeply into chemical reactions, it serves as a critical reminder of how important it is to check with a qualified person. Remember…just because a vessel has been out of service for a long period of time does not mean there are no hazards present!

The following article was featured in the June 2014 issue of ISHN, and authored by Roco Chief Instructor Pat Furr.

As part of my safety consulting duties, I have seen many fall protection programs for a wide variety of industries. When I ask about an employer’s fall protection plan, it’s pretty scary to be told, “Well, I can show you our program in two minutes”— and then see no more than a locker with a rag-tag assortment of body belts, harnesses and a few six- foot energy-absorbing lanyards of questionable integrity.

Now, it is rare to come across such an inadequate program. But truth be told, the comprehensiveness, diligence and effectiveness of the programs I have assessed run a fairly wide spectrum from so-so to top notch.

Top-notch programs all had several common elements, but the one element that stands out the most as being consistently included in the best programs is the completion of fall hazard surveys.

A Comprehensive Survey

The fall hazard survey, or what I like to call the fall hazard “walk-about,” is a critical early step in the process of assembling a comprehensive managed fall protection program. And a survey should be conducted again when certain changes occur including, but not limited to, changes in the facility configuration, changes to work processes, changes to legislated requirements, and the emergence of modern fall protection equipment solutions.

Outlined in ANSI Z359.2, the fall hazard survey is an effective means to identify areas where work is performed at height, identify ways to eliminate or control fall hazards, and help determine which hazards require the highest priority when it comes to allocating sometimes limited resources. A comprehensive fall hazard survey is the best way to identify and understand the types of fall hazards that need to be addressed to provide the best protection to your workers at height.

This requires that the Qualified or Competent Person do a top to bottom, left to right, tour of the facility to identify known areas where work at height is currently being performed, and any areas where future work at height may take place.

It may be helpful to have an area foreman or even an Authorized Person with thorough knowledge of the specific work areas available to ask questions regarding the work process and their needs and concerns.

The goal of this survey is to not only identify areas of work at height, but to determine the most protective means of abating the fall hazards.

 
The goal of this survey is to not only identify areas of work at height, but to determine the most protective means of abating fall hazards.

The Qualified/Competent Person must have the “Hierarchy of Fall Protection” in mind at all times. By having the goal of eliminating the fall hazard first and foremost, any opportunities to bring the work to the ground or to perform the work from the ground should present themselves during this survey. This may require a change in the configuration of certain structures, or the retrofitting of systems that allow the work to be performed from the ground. This may incur some significant costs, but in the long run the changes will be more than offset by avoiding a fall from height and the direct and indirect costs of such an accident.

Continuing the survey while still adhering to the Hierarchy of Fall Protection, the Qualified/ Competent Person may have to consider the use of fall restraint measures, either passive measures in the form of guardrails or parapets, or active measures in the form of body belts or harnesses with lanyards anchored in a way that the system prevents the Authorized Worker from reaching the leading edge of a fall hazard. Once active measures are employed, it is critically important to work with the Authorized Persons to understand what their work activities entail to come to a solution that provides the needed protection but also considers their need for mobility.

If the lower echelons of the Hierarchy of Fall Protection cannot be employed, a fall arrest system may be the only feasible solution.
 

A Fall Arrest Solution

If the lower echelons of the Hierarchy of Fall Protection cannot be employed, a fall arrest system may be the only feasible solution. This is where the Qualified/Competent Person’s knowledge of current fall arrest systems and components really shows its value. Lightweight, breathable, multi-function fall protection equipment available today protects workers while also providing the ease of use and freedom of movement that has been missing for many years. This is an important tool that the Competent Person can use to their advantage when faced with any resistance from certain Authorized Persons.

During the fall hazard survey, consider the presence of any environmental factors that may affect the performance of the fall protection equipment or systems as well as an alternate solution, specialized materials, or even a reconfiguration of the structure/process. Environmental factors can include hot objects, sharp edges, slowly engulfing materials, chemicals, weather factors, or any other environmental factor that may render the fall protection equipment ineffective.

Document Findings

Once the entire facility has been surveyed, it’s time to document in writing the findings and the means to abate the identified fall hazards. The Fall Hazard Survey Report becomes a part of the written fall protection program. It should be reviewed periodically and whenever there is a change to legislated requirements or a change in the facility or fall protection equipment.

Plan for Rescue

If any identified areas require the use of fall arrest systems, then that triggers the need to complete a written rescue pre-plan. It is my opinion that rescue

If any identified areas require the use of fall arrest systems, then that triggers the need to complete a written rescue pre-plan.

 
pre-plans should also include anywhere workers are performing work at height, such as elevated platforms that have been accessed by means other than elevators or stairs, with the goal that the rescue plan provides a capability to get the injured or suddenly ill worker to the ground promptly.

Time to Train

Once the Fall Hazard Survey is completed and documented, it is time for the Qualified Competent Person to provide training to the Authorized Persons on the types of equipment, systems, selection of anchor points, clearance requirements, swing fall hazards, and pre-use inspections of their equipment. Training may vary depending on the areas that Authorized Persons are assigned duties, but in all cases the type of training, any required re-training, and the criteria that would trigger the need for retraining must be documented.

A Valuable Tool

The fall hazard survey is a valuable tool that provides a thorough assessment of the entire facility to honestly identify fall hazards and determine the most effective means to protect workers from falls. Look at it as an expanded JHA that focuses specifically on areas of work at height.

Recently, we noticed a story in a leading safety and health magazine that questions the “two-piece, pass-through buckle” that is commonly used on many harnesses. The author, in fact, referred to it as a design flaw. However, we consider it more a matter of improper use than a design flaw. While he does identify some potential user failures, we feel his terming is not quite accurate. Here’s why...

As with any life support equipment, it is imperative to use the equipment in accordance with the manufacturer’s instructions for use and receive the appropriate training as required. The author cites instances where he has observed the mating plate of the two-piece, pass-through buckle being improperly oriented which can lead to the buckle loosening and potentially disconnecting. He also suggests that the pass-through plate have some type of “visual indicator” to warn the user when the buckle is improperly connected. Of course, we’re always in favor of additional safety features!

While this may be viewed as a matter of semantics, consider the following analogy… almost every outboard motorboat has one or sometimes multiple drain plugs in the transom well to provide drainage once the boat is pulled out of the water. If the skipper forgets to re-install the drain plugs the next time the boat is launched, the transom well will fill with water, which could lead to swamping. So, is this a design flaw, or improper use? From an equipment designer/manufacturer’s point of view, the use of this terminology could be very significant.

With the many advances in life safety equipment, we have seen harnesses and other rescue/safety equipment become more convenient, lighter, multifunctional, and overall safer than earlier generations. As with many product advances and improvements, there may be compromise in one area but advances in many others. In this case, the speed and ease of donning and doffing a Class III rescue or fall protection harness by using some type of quick-connect buckle. Of course, the user must ensure that the buckle is used correctly.

The pass-through buckle has been around a very long time. In fact, a Croll sport climbing sit harness that I bought in 1981 had this type buckle. These buckles were also used in the past on the leg loops on Roco harnesses. There are minor variations on the design of the buckle with some having slots to ease the pass-through of the top plate, while others do not have this slot.

There are important requirements for the safe use of these buckles, which include:

1. Make sure the buckle is adjusted tightly enough to ensure constant tension is applied to the top plate against the fixed plate.
2. Be sure that the top plate is not inverted.
3. Double check that the tail end of the webbing does not pass through the “fixed plate” but instead lays parallel with the anchored section of the webbing.

These three user points of performance are easily completed. Our extensive experience with this type of buckle tells us that it’s a convenient and safe buckle when used as it was designed. As always, carefully check and re-check your gear before life-loading!

Information from article by Robert Peterson published by OH&S Online - www.ohsonline.com.

Additional Resources

Gear Inspection Checklist (download)

How often should I replace my rescue harness?

Rope Care & Cleaning Tips