Fires in the Shredder Pile

Oct 6, 2017, 19:39 PM
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May/June 2016

New fire hazards could be lurking in cars, ovens, and other shredder infeed material—or in piles of shredder residue. Here’s how to reduce your risks. 

By Katie Pyzyk

In an instant, a spark can lead to a flame. In one more blink of an eye, an entire shredder stockpile can become engulfed in fire. By then the damage is done—both to a scrapyard’s property and perhaps to its reputation within the community. Every scrap recycler tries to avoid that scenario, but shredder pile fires have become a persistent and elusive problem, affecting the stockpiles of incoming materials awaiting shredding and, to a lesser extent, the stockpiles of automobile shredder residue, or fluff.

George Adams, president and CEO of SA Recycling (Orange, Calif.), is convinced shredder pile fires have increased over the last decade. That statistic is difficult to track accurately, however, because many small fires go unreported. Still, there are several reasons Adams could be right. A host of new, less well known (and less visible) hazards are coming into the yard, tucked away in everything from automobiles and ovens to wristwatches and smartphones. And recyclers might not be running their shredders as frequently as they would in better times, letting infeed piles build up to higher levels. As recycling and firefighting professionals become more experienced with such hazards, however, they are developing strategies for avoiding potentially costly pile fires.

Assault by Battery

Adams is among those who view the increasing presence of rechargeable lithium-ion batteries as a serious fire threat in shredder piles. Consumer product manufacturers tout lithium-ion batteries’ rechargeability and long life; they’re also smaller and lighter than other batteries, making them ideal for a range of increasingly popular products such as smartphones and some e-cigarettes. But they also carry an unsettling reputation for spontaneous combustion. Some critics consider these tiny items one of the culprits behind the recent spate of hoverboard fires, for example. While spontaneous combustion is not necessarily a common occurrence in lithium-ion batteries, it happens often enough to pose a legitimate safety concern.

Fires can occur when lithium-ion batteries short-circuit, which typically results from battery damage, namely to the thin separators that keep the internal elements of the battery apart. When the elements touch, the battery will fail, and when lithium-ion batteries fail, they “get extremely hot … hot enough that they can catch ordinary combustibles on fire around them,” says Waukesha (Wis.) Fire Marshal Brian Charlesworth. Leaving the batteries in warm environments can exacerbate the problem, as can manufacturing flaws within the batteries themselves. Battery damage also can occur from impact, such as in an infeed pile where “the way the pile [is] crushing down over the course of the day” can put pressure on those separators, which “tends to set them off and they catch on fire,” according to Adams.

The challenge is to identify the potential hazard before it gets into an infeed pile. “The batteries are a huge [issue],” Charlesworth says. “You have to do everything you can to make sure you don’t get a battery in that pile because that introduces an energy source that could easily ignite something if it shorted out.”

Other hazards to look for in incoming scrap include nonrechargeable lithium batteries, common in such small items as flashlights and toys. These can be dangerous because the lithium metal used for the anode reacts explosively when it comes in contact with water.

Several common materials also consistently prove troublesome as risks in inbound shredder feed stockpiles, such as scrap automobiles that inadvertently contain a lead-acid battery, according to Steve Shinn, West regional president for Sims Metal Management (New York). “Certain items, such as gas tanks with residual gasoline, gas cylinders, and auto batteries, are well-known [hazards],” he says, in addition to some grill spark ignitors or home oven temperature sensors containing NaK, or sodium-potassium alloy, which reacts explosively with water. NaK can be a problem in both infeed material piles and ASR piles if even a small amount of the material is present. ISRI has warned members of this phenomenon for years, most recently in 2015, after an association member reported that some self-cleaning oven sensor pieces likely sparked a residue pile fire at one of its yards. Carefully removing and properly disposing of the sensors before putting the oven in an infeed pile is a viable alternative to simply not accepting ovens as scrap.

Risks in the Residue

Shredder residue piles have their own dangers due to materials heating up while going through the shredding process and then sitting among combustibles. ASR tends to contain a lot of rubber, plastics, and foam, which means it can burn particularly hot, Charlesworth explains. “You want to limit the size of that pile more than you would a pile that’s just got a lot of scrap metal that’s waiting to be shredded,” he recommends.

Robert Weber, president of Garden Street Iron & Metal (Fort Myers, Fla.), has only experienced two infeed pile fires in his 30 years with the company, but ASR piles are a different story, he notes. “I think we’ve had more fires in [residue] piles than anything else I’ve ever seen in the industry,” he says.

Fires tend to spark so deep within a pile and to burn so hot that they destroy everything surrounding them. That makes it difficult to determine the source of the problem. Further, these piles often weigh hundreds of tons and tower dozens of feet in height, making it difficult for fire departments, scrapyard employees, or investigators to put such fires out. “It’s a lot more challenging because the fire can burn down inside the pile and you can’t see it, so it’s hard to get to what we call the ‘seat’ of the fire with water,” Charlesworth says.

The Waukesha Fire Department handled such a fire last year. The scrapyard workers eventually had to use their heavy equipment to “pull the pile apart and spread the debris on the ground,” Charlesworth says. “Then we just continued to work through the pile until we spread the pile out and got water on everything.”

Controlling Risk

Managing both the content and the size of shredder piles is the key to controlling the risk of fire, these sources say.

Fire-sparking items can’t get into an infeed stockpile if they don’t make it into the recycling facility in the first place. Shinn emphasizes the need for “robust inspection activity” to stop certain materials from getting into inbound scrap. Sims trains those who check incoming scrap to identify potentially risky items, such as compressed gas containers and batteries, which may be explosive or create sparks when crushed or punctured.

On the other hand, the sources may not always be easily visible during initial inspections, such as with lithium-ion batteries. A rogue cell phone or electronic cigarette containing a lithium-ion battery could be left in an end-of-life vehicle that arrives at a scrapyard. “I think it’s almost impossible to find these little lithium batteries, and I think they’re in everything,” Adams says. Also, some scrap businesses purchase partially processed material from other companies. A crushed, logged, or baled car can’t have its trunk or glove compartment searched for hazards. The company supplying such material should be inspecting it prior to processing, Shinn says. If Sims has problems with a third party, it will “give feedback to the supplier so they can do a better job” of removing unwanted items, he says.

Safety measures such as turning away potentially hazardous items are easier when times are good. With the current state of the scrap industry, Adams points out, it’s hard to turn away any customers, even those supplying undesirable items. “If you’re not going to buy scrap because there [may be] a lithium-ion battery in it, that’s a very high percent of your volume” you may be turning away, he says.

In the long term, “we’ve also got to look at changes … [in] raw materials and continue to update our programs” when new potential hazards appear, Shinn says. One such trend on the horizon is the growing prevalence of hybrid and plug-in electric vehicles. Some of the latter use lithium-ion batteries. Shinn believes it will be a “fairly long period of time before a critical mass of hybrid and electric vehicles hits the recyclers,” but by the same token, he says, “I think it would be helpful to be proactive, especially in areas where there’s a higher likelihood of finding those vehicles.” Meaning, metal recyclers should anticipate accepting electric vehicles and start learning now how to handle them properly to mitigate any potential fire threat. Other recent changes to the raw material stream include rechargeable household devices and toys, Shinn adds.

Pile Management

Controlling fire hazards in shredder stockpiles isn’t only about limiting what comes into the scrapyard, but also about keeping tabs on what’s already on the premises. The one nearly universally recommended practice is to keep material flowing and prevent it from accumulating into large, unmanageable stockpiles. Some recyclers, such as Garden Street’s Weber, recommend segregating infeed piles by material type, such as automobiles or white goods. Also, “having no [infeed] material stockpiles at the end of your business day is a great way of eliminating that risk,” Shinn says. “If you can shred to the ground … you really eliminate any potential for infeed stockpile fires.” He adds that the same is true of ASR: “The less ASR is stockpiled at the end of the business day, the less chance [there is] for an ASR stockpile fire.”

Try to maintain adequate space between piles to keep fires from spreading. “If [one] catches on fire, you’re dealing with a small pile,” Adams points out. It’s easier and safer to maneuver among well-spaced piles both during daily operations and in an emergency situation. This strategy is also important for combating fires when they do happen. “You have to have a layout of your plant that allows for quick and easy [firefighter] access,” Shinn says.

As for maximum pile size, “there’s no standard or code that says what is a good size, so it’s somewhat subjective,” Charlesworth says, emphasizing that it’s still key to “limit the pile size and keep them separated.” Fires in small piles are easier to fight.

Difficult times for the scrap industry also make it harder to limit pile sizes, however. “The piles build up because people try to run their shredders as efficiently as possible. … So they let [the infeed] build up three days [or] four days” or even longer, Adams says. “Then they shred because they have a bunch of stuff to shred, and they let it build up again.” Such tactics are understandable, but “when people let big piles build up, they take a risk, like Russian roulette, with their shredder and with a fire,” Adams says.

Garden Street tries to keep its piles “organized and keep them in a nice area,” Weber says, adding that the Florida Department of Environmental Protection “appreciates the fact that we have a roof over [our residue pile] to keep it from being in the weather.” He stresses that not keeping a lot of raw or processed material on site is the main thing. “We have two trucks that do continuously run back and forth to the landfill delivering the fluff, getting it out of our yard,” he says. “If there are days we’re not running [the shredder] we could get caught up. We keep our trucks moving.”

Response Planning

When a fire breaks out, there could be mere seconds to act correctly to save lives and property, so employees need to be well-versed in the company’s fire response procedures and equipment. Regularly scheduled fire drills are one way to impart that knowledge.

In addition to practicing evacuation procedures, the drills should test equipment to ensure water systems and fire suppression chemicals will function properly in an actual emergency. “Every month, you physically drag your hoses out, you spray the water, and people know where it is and how to turn it on and off,” Adams says. Have the yard inspected for up-to-date and functioning fire extinguishers, adequate water pressure, and hoses that are long enough and powerful enough to deliver water to all parts of all piles. “You see people trying to fight a fire with a 5/8-inch garden hose. That won’t even put out enough water to talk about,” Adams says. He also notes the importance of keeping hoses covered or out of the sun. He’s seen hoses that have “been sitting out in the sun for years, and they’re all rotted. The first time they go to pull that hose, it’s all going to crack.”

“Recycling businesses need also to consider investment in fire mitigation and suppression systems or equipment, such as sprinklers or extinguishers,” Shinn says. “Encapsulating agents, developed by NASCAR to extinguish auto fires, are also widely available today to enhance any facility’s fire-suppression capabilities.”

Dennis Graff, safety training officer at the Waukesha Fire Department, warns scrapyard workers not to put themselves into precarious positions, such as by stretching the hose lines or exposing themselves to toxic smoke by not wearing appropriate personal protective equipment. Smoke exposure can “cause disorientation, poor judgment, and inability to self-rescue,” he says. He recommends that scrapyard employees who encounter a fire “leave it to the specially trained firefighters,” but you can “be at the ready to provide information [to the firefighters] on contents of the scrap pile, critical information on processes and hazards on the property potentially [affected] by the fire, and … personnel to operate heavy equipment for purposes of deconstructing burning piles.”

“Everyone should establish, or re-establish, a dialogue with local firefighters to ensure all are well-prepared for managing a potential scrap metal stockpile fire,” Shinn says.

Under a Watchful (Electronic) Eye

Fire-monitoring technology can help detect and respond to shredder pile fires. “Off-site monitoring provides not just security for the facility, but also heat detection for stockpiles,” Shinn says. Many of the available thermal imaging systems monitor stockpile temperatures as well as changes in temperature over time, which could indicate trouble inside the stockpile. “As the algorithms used to detect temperature changes further develop, they become very effective at anticipating and predicting the occurrence of a fire,” Shinn says. After business hours, such predictions allow the security service provider to alert the designated facility contact, who can then take measures to further investigate, break up a potential hot spot, or contact 911 to extinguish a fire before it grows out of control. “It’s a much more robust solution compared with staff security that is just able to walk around and do rounds. Continuous monitoring of video images is superior to occasional walks around your facility,” he says.

Garden Street’s system of more than 70 infrared cameras has helped to catch “probably a half dozen or so” fires in their early stages, according to Weber. “They’re really effective” and can be turned toward “the [shredder residue] bunker or any machine where we’re worried about something happening.”

Although the proper fire prevention and mitigation tools can be pricey, they’re a worthwhile investment, scrapyard managers say. “Some people don’t want to spend the money, but then they end up spending the money if they … end up having a big fire” and lose their infeed materials or property, Adams says.

That said, hand-held heat detection equipment offers a relatively similar, smaller-scale option for scrapyards that don’t have the means to invest in off-site monitoring. Some shredder plants have had success with regularly using such devices to confirm that a feedstock or residue pile’s internal temperature isn’t climbing.

At least one company has a remote system that augments the thermal imaging camera with a foam-dispersing unit. Watchdog Security’s (Southfield, Mich.) Fire Rover system has 343-degree rotation and detects and extinguishes fires up to 150 feet away, the company says.

The Cost of Fire Loss

Shredder pile fires can be expensive. Scrapyards potentially have costs associated with extinguishing the fire, lost infeed or processed materials, environmental cleanup, and facility damage. For the biggest fires, add to that time and money spent trying to regain the trust of regulators and surrounding communities.

A particularly disheartening aspect of shredder residue fires is that most scrapyards’ insurance won’t cover that material if it catches fire, which means the cost of fighting the fire isn’t necessarily covered, either. “If the building is on fire, which is typically insured, the insurance company will pay for the cost of putting the fire out and [repairing] damage to the building,” says Ron Hallmark, president of Hibbs-Hallmark & Co. (Tyler, Texas) and founder of the Recycle-Pro insurance program. “With fluff, … insurance doesn’t cover it, and the state typically requires you [to bear the costs] to put [the fire] out.” For one of his clients, a lightning strike was to blame. “It sparked on a really large fluff pile. … Lightning had a direct hit on it and set off a really nasty fire,” Hallmark says. “The fire department couldn’t put it out, [so the client] ended up having to hire a special oil and gas crew to come put it out. It was tremendously expensive.”

A major shredder stockpile fire can create significant reputational costs not only for the individual business where it occurred, but also for the entire metal recycling industry. “We really need to be responsible not just for ourselves, but for the greater good of the industry,” Shinn says. “If we’re not, there may well be regulatory and legislative steps taken to impose conditions that may make it more onerous for businesses to operate.” 

Katie Pyzyk is a contributing writer for Scrap.


Shredder Fire Hazards Beyond the Piles

Shredder pile fires aren’t only caused by hot, explosive, or flammable materials making their way into the facility; improper shredder plant operating procedures also can spark fires.

Shredders themselves cause enough friction to throw both sparks and hot material pieces. Just one small piece of hot metal falling into a pile of dust or debris can easily spark a fire, which then can spread. Poor shredder maintenance—on the conveyors, feed chute, or size-reduction equipment—also can create dangerous amounts of friction and sparks.

Like many other scrap recyclers, Garden Street Iron & Metal (Fort Myers, Fla.) sends its materials through downstream processing to ensure it has performed the maximum metal separation. “During the first run, we’re running the shredder, and [material] comes right off the shredder and goes into the bunker,” says Garden Street President Robert Weber. “That’s where we tend to have the issues,” when a shredder throws a hot piece of metal and it smolders in a shredded material pile for a while. To minimize that risk, keep feedstock and residue piles away from the machinery and limit dust and debris in, around, and under the shredder.

Flammable fluids are common in and around shredders, but they create a serious danger if not controlled. Scott Newell, chairman of Newell Recycling Equipment (El Paso, Texas), says if he approaches a shredder and sees oil on the ground, he’ll tell employees “it’s something they have to address right this minute—you can’t run for even another 10 minutes like this. Clean it up, find the source of the problem, and fix it. … I do not allow sloppy housekeeping around the machine.” It’s also essential to “keep torches and welding [equipment] and open fires away from those segregated [shredder] piles,” he says.

“I think we have really good housekeeping, and yet it still happens to me,” says George Adams, president and CEO of SA Recycling (Orange, Calif.), about fires in and around the shredder. One of his facilities experienced a fire in the shredder tower after welders working on a panel near the shredder left for the day. They did not realize that a spark had made its way between the tower and building, where it smoldered for hours and later caught fire. “A small flame started burning the flashing, and the next thing you know, we have a raging fire,” Adams recalls. “We would have lost the whole shredder tower, which would have been a lot of damage, except for the fact that we do fire drills all the time,” and everyone knew how to extinguish the fire, he says.

New fire hazards could be lurking in cars, ovens, and other shredder infeed material—or in piles of shredder residue. Here’s how to reduce your risks. 
  • 2016
  • May_Jun

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