On Feb. 7, 2008, a combustible dust explosion ripped through the Imperial Sugar Co. refinery in Port Wentworth, Ga., killing 14 employees and injuring dozens. The incident triggered $8 million in proposed OSHA fines, a Senate hearing, a renewed call for an OSHA standard and widespread concerns about combustible dust hazards. It also prompted Imperial Sugar to make some changes in its facilities and procedures — including outfitting all workers in fire-resistant (FR) clothing.
“Post-event, we have required all employees and visitors to the manufacturing areas to wear fire-resistant clothing. It's a blanket requirement and one that is we believe quite conservative,” says Ron Allen, who joined Imperial Sugar as senior director of environmental, health, safety and quality in March 2009. “It's probably unusual for a manufacturer of dry product to require fire-resistant clothing plant-wide for all employees.”
Approximately 700 Imperial Sugar workers — about 400 in the rebuilt Port Wentworth facility, as well as 300 at the company's Grammercy, La., plant — must wear FR garments. All contractors and site visitors must don the protective clothing as well.
Imperial Sugar provides combinations of FR pants, shirts and coveralls. The uniforms are rated for 100 washes, and the garments carefully are monitored so they do not exceed that wash requirement. Electricians and welders wear a higher performing fabric to protect them from arc flash.
Scott Margolin, international technical director at Westex Inc., acknowledges that in the event of a combustible dust incident, some fatalities may be unavoidable because of explosions, entrapment or sustained fire. But “vastly more people” often are involved in the flash fire portion of the event, he says.
“If it doesn't ignite your clothes, you're probably going to live. And if it does, you're probably not,” Margolin says. “FR clothing can make a huge contribution to worker safety in that area.”
FR clothing is designed to protect workers from arc flash and flash fire, two hazards that can cause serious injury or death. In an arc flash, the amount of energy released is “quite significant,” with temperatures reaching between 10 and 20,000 degrees Fahrenheit, explains Dan Bowen, technical marketing specialist for Dupont Personal Protection.
“Even though the duration of an arc flash is usually fairly short, on the order of less than 1 second, the amount of intense heat will cause anything combustible to burst into flames almost immediately,” Bowen says. “There's been a tremendous amount of people injured and killed by arc flash events that suffer badly because the clothing they were wearing caught on fire.”
Bowen explains that workers' clothing plays a big role in the extent of their injuries in the event of an arc flash, especially if they are wearing a synthetic blend such as polypropylene or nylon blends.
“The challenge with those fabrics is not only will they ignite, but they'll burn vigorously because they're plastic,” Bowen says. “They are highly flammable. They melt, they burn, they drip. They make a bad matter much worse.”
When FR clothing is exposed to a heat source and that heat source is then removed, the garment will not continue to burn, Bowen explains. “That's not to say these things are fire proof. It's not like wearing cement or steel — they will undergo a physical change — but as soon as the heat source is gone, that fabric won't burn. It's designed to provide protection for the worker from that burn injury.”
Margolin adds that if a worker's street clothes ignite, the fire and subsequent burn injuries will spread to areas of the body where the arc itself never touched.
“As silly as this sounds, you're literally better off naked because the body burn injury you would suffer is going to be limited to the areas of the body where the arc hits. [If] your garments ignite, that fire is going to spread very rapidly,” he says. “As soon as the shirt ignites, you're shifting from survivable or no injury with FR clothing, to potentially or probably fatal injury [without FR clothing] within seconds.”
FR clothing also provides protection through insulation, shielding the body from the heat of the event.
“The analogy that I like to make is you wouldn't wear a windbreaker out into a blizzard, would you?” Margolin says. “If you know it's 55 degrees out, you can put a windbreaker on and you're going to okay. If it's 55 degrees out, you're not going to wear that same lightweight jacket — you're dressing appropriately to that hazard, in this case cold.”
As with any PPE, workers and safety professionals must have a full understanding of the equipment to properly and safely use it. Misconceptions about FR clothing can be dangerous. For example, Margolin cites the erroneous belief that cotton is an upgrade from synthetic blend materials. While cotton doesn't melt, wearing cotton garments in the event of arc flash or a flash fire could be deadly.
“Cotton ignites just as readily as poly cotton, and it burns hotter, meaning it will do more damage to your skin more quickly,” Margolin says. “It's harder to extinguish and it's typically heavier, which means more fuel for a longer fire. Cotton is not an upgrade. It does ignite, and it's equally hazardous.”
Another troubling misconception is that workers need an FR shirt or jacket but not FR pants. Not wearing full protection, Margolin warns, is a dangerous move.
“You wouldn't do that any more than you would wear half a hard hat or one lens of a safety glass, or just the right glove for shock protection but not the left one,” he says. “A shirt-only program is not a program at all. You're not compliant, [and] you're not going to save yourself the fatalities or medical costs.”
Finally, Margolin stresses that not all FR is the same.
“Just because something has an arc rating doesn't mean it's a long-term, viable product, so we urge people to look for market-proven products,” he says. “There is no excuse in our business today to wear a garment where you have to count the launderings. There are plenty of fabrics out there that are flame resistant for the life of the garment. I would urge people to look for market-proven products.”
Bowen adds that when it comes to FR clothing and protection from flash fire, some safety professionals are content with doing only the bare minimum to remain compliant.
“With flash fire, everyone looks at the lowest possible denominator, but every place else they're willing to step up and look at the hazard,” Bowen says. “Nobody skimps on respirators. Employers will purchase and mandate that their employees use the correct level of respiratory protection, but they don't do the same thing with flash fire.”
Another commonly misunderstand aspect of FR clothing is how comfortable it can be.
“There's a misconception that flame-resistant clothing is heavier, stiffer, scratchier or uglier than street clothing. That's one of the reasons people don't get it,” Margolin says. “We have been engineering for years trying to get lighter and lighter and softer and softer and more and more street looking. And with at least a few brands, we have gotten there.”
Lanny Floyd, principal consultant for electrical safety and technology at Dupont, agrees that FR garments today are being developed for higher performance and lower weight. “Over the last 10 years, there have been significant advances in the comfort and usability” of FR fabrics, he explains. Additionally, the face shields and hoods used in arc flash protection also have been improved.
To find the FR fabric and clothing that will be most comfortable for workers, Bowen suggests that safety professionals conduct a wear trial. Identify several different fabric types and fabric manufacturers and obtain sample garments. Let workers wear these garments in real-life work situations so they can determine what feels best.
“Look at the job that needs to be performed, look at the features you want on the garment, identify a few options, put it on people and let them wear it for a couple of months,” Bowen says.
LAST LINE OF DEFENSE
Floyd also stresses that workers must know how to properly wear and use FR clothing. That means securing all fasteners, ensuring all body parts are protected, never rolling up sleeves and repairing any damage immediately and with the appropriate materials, such as FR thread.
Users also must follow the garment manufacturer's instruction on care and cleaning. Don't allow contaminated materials, solvent or grease that could ignite and degrade the performance of the protective clothing come into contact with the garments.
Finally, Floyd explains that one of the big areas of opportunities in the FR world is education on when and how to use these garments properly.
“That's one of the big gaps I think we have today,” Floyd considers. “We have great products and great standards to improve safety for workers, but making sure people understand how to use it properly is always a challenge. Ongoing education is very important.”
Being properly educated often means staying up-to-date on timely topics, such as combustible dust.
“Combustible dust is hot-button issue with OSHA and FR,” says Margolin, who attended the December 2009 OSHA stakeholder meetings on the development of a combustible dust standard (see sidebar on page 22). “The first line of defense of any of these things is to engineer the hazard out or down,” he explains.
“Flame-resistant clothing, while it is admittedly the last line of defense after behavioral and engineering safety have been addressed, cannot and must not be overlooked. Just because a car has crumple zones and impact-absorbing bumpers and air bags does not mean you can forget to put on your seat belt,” Margolin says. “Same kind of logic.”
A COMBUSTIBLE DUST STANDARD
On Oct. 21, 2009, OSHA published an Advance Notice of Proposed Rulemaking as an initial step in developing a standard to address the hazards of combustible dust. Ron Allen represented Imperial Sugar at OSHA's Dec. 14, 2009, stakeholder meetings on this issue.
“We are strong advocates for an OSHA standard,” he says. “I came away [from the stakeholder meeting] with an appreciation that there are many different opinions that will influence the final standard.”
According to Allen, OSHA representatives “seemed to sincerely have an open mind and are listening to the various stakeholders as they attempt to put together this new standard.” He adds that he'd like to see a combustible dust standard with specification language as opposed to performance language.
“Performance standards are very attractive on the surface, but could be much more difficult to administer than a specification standard,” he points out. “We think that specification language actually serves as an education. It helps employers, particularly small employers, who may not have a great deal of technical resource to understand what they must do to protect their employees from combustible dust fires and explosions.”
A Cost-Effective Solution
“OSHA has clearly embarked on a path that's going to result in a rule on combustible dust,” says Margolin, who also attended the combustible dust stakeholder meetings. “The big questions to me seem to be about scope, and what language [of existing NFPA standards], if any, will make it in.”
According to Margolin, the meetings focused on existing NFPA consensus standards, the potential scope of a standard, economic impact and hazard mitigation. FR clothing also entered the discussion, particularly in terms of economic impact. Margolin is quick to point out just how cost-efficient FR clothing can be.
“Body burn is the second most expensive hospitalization in the U.S.,” he says. “Putting everybody who remotely needs FR clothing in it for the rest of their careers costs vastly less than the first year of medical [expenses] alone for the burn injuries that are already happening, much less the ongoing medical costs, insurance, workers compensation, counseling, fines and lawsuits.”
Overall, Margolin was encouraged by what he calls an obvious intent to develop and implement a standard for combustible dust.
“It's not a matter of if but when they will put out a rule on combustible dust,” he says.