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Saws Cut Off 4,000 Fingers a Year. This Gadget Could Fix That.

So why are the big power tool companies refusing to use it?

| Thu May 16, 2013 6:00 AM EDT

A longer version of this story appears at FairWarning.

Gerald Wheeler caught the hot dog demonstration at the International Woodworking Fair in Atlanta in 2002. A man took an Oscar Meyer wiener and pushed it into the blade of a table saw spinning 4,000 times per minute. As the hot dog touched the whirring saw, the blade came to a dead stop in about three one-thousandths of a second, leaving the dog with only a minor nick.

The saw was equipped with a safety device called SawStop that could distinguish between wood and flesh and then stop the blade fast enough to prevent a gruesome injury. Wheeler was amazed. As the operator of a wood shop in Hot Springs, Arkansas, he was all too aware of the unforgiving nature of table saws. Not long before, two of his employees had been maimed within a few weeks of each other. Wheeler felt awful about the injuries, the loss of two good workers, the $95,000 in medical bills, the doubling of his workers compensation rates. Watching SawStop in action, Wheeler thought: If only this had come along sooner.

Those kinds of injuries are all too common: Each year, more than 67,000 workers and do-it-yourselfers are injured by table saws, according to the Consumer Product Safety Commission (PDF), resulting in more than 33,000 emergency room visits and 4,000 amputations. At an average cost of $35,000 each, these accidents lead to more than $2.3 billion in societal costs annually including medical bills, lost wages, and pain and suffering.

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Since it started making table saws in in 2004, SawStop has recorded 2,000 "finger saves"—customer reports of accidents likely to have caused disfiguring injuries with conventional saws, but that resulted in minor cuts or a few stitches at most. (SawStop also has acknowledged two reports of amputations.) Wheeler bought two of the company's first saws. In March 2006, Carl Seymour, a foreman at his shop, accidentally touched a whirring blade. A photo on SawStop's website shows Seymour beaming in triumph as he displays his thumb, which looks like it has a paper cut. "You couldn't wipe the smile off him after this," Wheeler says, adding that he, too, was "totally ecstatic." All saws should have this technology, Wheeler says. "I mean, we're dealing with human beings."

However, SawStop still makes the only saws with skin-sensing technology, and accounts for a tiny fraction of total saw sales. Tens of thousands of digits have been sliced off in the past decade, but the rest of power tool industry has snubbed the technology and carried on as before.

Gass says a power tool executive warned him, "If you guys don't cooperate with us, the industry is going to get together and squish you."

For more than a decade, toolmakers and the Power Tool Institute, their trade group, have defended the design of conventional table saws and their decision to not adopt SawStop or a similar safety device. Publicly they've offered several arguments: The number of saw injuries and their impact are exaggerated; the market for popular, lightweight saws, which cost as little as $100, would be destroyed by the added expense of SawStop; SawStop may stop a blade when it touches conductive materials like metal or very wet wood, usually destroying the blade. But as court records and testimony have shown, the power tool companies have rejected the safety advance for another reason: They are worried that if a new way to prevent severe injuries became widespread, they would face a wave of liability suits for accidents involving conventional saws.

The SawStop story is about an industry's ability to resist a major safety advance that could have prevented countless disfiguring injuries, but might have been bad for business. It also highlights the bureaucratic obstacles that make it virtually impossible for regulators to enact safety measures over the unified objections of industry. The power tool industry representatives contacted for this story declined interview requests or did not return calls and emails. The Robert Bosch Tool Corporation provided a statement: "Safety has historically been one of the Bosch principles…and is reflected in our slogan 'Invented for life.'"

"Safety doesn't sell"

Stephen Gass, an energetic, intense 49-year-old, grew up on a horse farm in eastern Oregon and learned woodworking from his father. He earned a doctorate in physics and a law degree, then joined a patent law firm in Portland, but never lost his interest in building things. One fall day in 1999, while out in his home workshop, he was struck by a question: Would it be possible to stop a table saw quickly enough to keep it from slicing off your fingers? After a doing a series of calculations and using parts you could buy at Radio Shack, he showed it could be done.

His invention works by running a weak electrical current through the saw blade. When someone comes in contact with the blade, the body absorbs part of the current. A sensor detects the change in current and activates a spring, which jams an aluminum wedge between the teeth of the blade, acting as a brake. The blade also drops below the surface of the table. It all happens so quickly that unless the hand is moving unusually fast when it hits the blade, any injury is minor.

It's a mystery why the power tool industry, with its engineering prowess, didn't invent SawStop before Gass did. Maybe it didn't because there were no clear financial or legal incentives to do so. Table saws are must-have tools for millions of construction workers, carpenters, and do-it-yourselfers. There are about 9.5 million of them in use in the United States. About 500,000 sold each year, 85 percent of them made by members of the Cleveland-based Power Tool Institute, which represents well-known brands such as Black & Decker, DeWalt, Makita, Skil, Bosch, and Ryobi.

For decades, the companies were shielded from liability by a few unquestioned assumptions: Table saws are inherently dangerous; everyone knows this; accidents typically involve carelessness or failure to follow directions; therefore, when people get hurt it is their own fault. As an industry lawyer told a jury in a recent injury lawsuit: "This is a table saw. It cuts wood. And if you're not careful, you can get injured."

The companies are guided by voluntary safety standards developed by an industry-dominated technical committee and Underwriters Laboratories. When SawStop came along, the voluntary standard called for table saws to have a guard that fits like a hood over the blade. Because a hand can slip under the guard, many thousands of injuries occurred even with the guard in place. However, the guard usually wasn't used. Because it limited visibility, had to be removed for certain cuts, and took a long time to detach and put on again, most saw users worked without it.

Gass thought his invention would be an easy sell. SawStop meant that saw makers now had the ability to prevent the tragedies they knew would happen otherwise. "I couldn't imagine that anyone would not want to put this on the saws that they were offering to people," he says. But the industry's initial reaction was not encouraging. Gass recalled one tool executive telling him, "The marketing guys say safety doesn't sell."

The industry took notice after Gass did the hot dog demo at the 2000 International Woodworking Fair and SawStop was awarded a top prize for technological advancement. Gass and his partners visited the offices of Black & Decker (now Stanley Black & Decker), Emerson Electric, Ryobi, and Bosch. In November 2000, they briefed members of the Power Tool Institute in Cleveland. Gass was overconfident. "We think you don't have any choice here," Gass recalls telling one executive. "It's the right thing to do. And if you don't do it, you're going to be liable for the injuries—and there's a lot of injuries happening." Still, the power tool companies seemed wary. Gass says a Black & Decker executive warned him, "If you guys don't cooperate with us, the industry is going to get together and squish you."

SawStop's prospects seemed to rise in July 2001 when CPSC engineers announced the results of a technical evaluation, finding that "The SawStop concept is valid and the prototype impressively demonstrates its feasibility." Ann Brown, then head of the agency, awarded SawStop a Chairman's Commendation for safety innovation. SawStop held negotiations with several companies, and nearly finalized a deal with Ryobi, but none ended up adopting the technology.

"Liability exposure has increased"

One of the power tool companies' main concerns about SawStop, court testimony and corporate documents reveal, was that it would worsen their liability risk. According to courtroom testimony by David Peot, Ryobi's former director of advanced technologies, "There certainly was a feeling that if a single company invents or improves a product that could have an effect on product liability, then other manufacturers could be at a disadvantage if they don't have that on their product."

Gass SawStop
SawStop inventor Stephen Gass with the patents for his company's safety device FairWarning

Without naming SawStop, an April 2002 Bosch memo, revealed in a lawsuit, warned of the threat from "competitive technology." The "expectation will be that the most severe injuries will be mild to moderate lacerations and that amputations will be virtually eliminated," it said. This "will create a new and significant liability concern for our corporation because of this enhanced safety performance." Or, as minutes of the Power Tool Institute's product liability committee in September 2002 put it: "Liability exposure has increased based on the product's introduction at IWF [International Woodworking Fair]."

"What the industry saw as a problem was not the amputations and injuries occurring on their product, but the advent of a technology that could prevent those injuries. That was the problem we created," says Gass. He recalled Peter Domeny, the former chairman of the Power Tool Institute's product liability committee and Bosch's director of product safety, telling him that SawStop had kept him awake wondering how the industry could defend itself from lawsuits. Domeny was questioned about this in 2008 at a deposition in the case of a Pennsylvania man who had four fingers amputated. "We had discussions as far as the liability implication, but not in that form as he [Gass] quotes it," Domeny replied. "I don't think I have discussed my sleep patterns with Mr. Gass."

Shut out by the toolmakers, Gass and his partners faced a stark choice: Either let their invention die or make their own saws. They chose the latter and raised $3 million from about 30 investors. Along with flesh-detection technology, the SawStop saws came with an important safety device called a riving knife that had been mostly limited to models sold in Europe. A riving knife is a curved steel blade that cuts the risk of "kickback," which occurs when a piece of wood suddenly jerks while being cut, sometimes pulling the operator’s hand into the blade. About 40,000 SawStop saws have been sold.

Each year, more than 67,000 people are injured by table saws, resulting in more than 4,000 amputations.

In response to the threat from SawStop, the power tool industry sprang into action. Five companies, including Black & Decker, Bosch, and Ryobi, formed a joint venture to develop their own injury reduction system. To head off possible antitrust problems, they alerted the Justice Department and Federal Trade Commission that they would pursue "research and development of technology for power saw blade contact injury avoidance, including skin sensing systems, blade braking systems, and/or blade guarding systems."

The joint venture ended in 2009, when the companies said they had developed a system superior to SawStop. Their design retracts the saw blade into the table immediately upon skin contact. Unlike SawStop, it does not use a brake, which damages the blade. Yet this safety system has yet to be offered in a single saw. Ryobi, Black & Decker, and Bosch did not return calls about when or if the technology will be used. Industry comments filed with the CPSC suggest that SawStop's patents were holding them back, potentially forcing them to pay royalties or engage in expensive patent litigation to roll out their system.

In April 2003, SawStop submitted a petition signed by more than 300 woodworkers, shop teachers, and others, asking the CPSC to require injury reduction technology. Prompted by the petition, in July 2006 the CPSC commissioners voted 2 to 1 to begin the initial stages of the rulemaking process. Yet within days of the vote, commission chairman Hal Stratton, who had voted yes, resigned to join a law firm. The resulting 1-1 stalemate meant the rulemaking notice could not be approved. It would be another five years before the commission would address the issue again. Yet while regulation stalled, the battle over table-saw injuries moved to the courts.

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