New CPSC Report: Human Factors in Table Saw Safety

Note: Executive editor Robert W. Lang was quoted in this article in USA Today.

The Consumer Product Safety Commission (CPSC) has issued a new report on table saw injuries, and the report is available online. It should be noted that this is a report by an engineering psychologist about how consumers interact with two things: the new style table saw guards and the SawStop braking system. The commission is likely to decide in the next few months whether or not to require “flesh-detecting technology” on table saws, as petitioned by SawStop. The report is well worth reading, as it sums up what table saw guards can and cannot do, and takes a look at the braking system.

The report offers a comparison of guards vs. brakes. Perhaps the most important point is this: Even the best guard can’t protect you if you let your attention lapse and put your hand under the guard as you’re pushing the stock into the blade. That seems almost too basic to be mentioned, but a lot of table saw accidents happen that way. Guards don’t exist to keep you from doing something you shouldn’t, they exist to mitigate the damage if and when you do. I wrote about the new guards when they first appeared in 2007.

The report also presents a discussion of the SawStop system, as tested by the CPSC staff. This system is actually a bit further down the line than guards when it comes to keeping you safe. The brake system is considered to be a secondary safety device; if something goes wrong and the guard doesn’t protect you, the brake will minimize the damage. One of the “human factors” that isn’t addressed in the report is this question: Are SawStop users more likely to take risks while using their saws? Statistically, SawStop owners make contact with the blade about three times as often as users of other saws, and this thread on SawMill Creek tells the story of one user’s kickback accident.

Two other items I found interesting in the report:

In a footnote at the bottom of page 15 is this reference to an alternative “flesh-detecting” technology:

“In a meeting with Commission staff in June 2011, the Power Tool Institute discussed and showed video footage of their technology, which also retracts the saw blade upon detecting blade contact with the skin. According to the Power Tool Institute, SawStop has stated that this system likely will infringe SawStop’s patents.”

And throughout the report, reference is made to this article from Popular Woodworking Magazine by Marc Adams. In the article, Marc details the forces at work as various cuts are made and how to make them safely. Let’s face it, table saws are dangerous – but nearly all of the danger can be eliminated if you learn safe procedures, are zealous in following them and devote your undivided attention to what you’re doing when you operate a table saw.

 Click here to read Marc Adams’s “Woodworking Essentials: Table Saws” article from Popular Woodworking Magazine.

Click here to read the CPSC report on the human factor in table saw injuries .

Click here to read about the new generation of table saw guards.

– Robert W. Lang

13 thoughts on “New CPSC Report: Human Factors in Table Saw Safety

  1. Macn

    Hi Robert,
    What concerns me is that in all the demonstations of the SawStop at Shows and on Video a frankfurt or similar is produced from the refrigerator resulting in an obviously damp/cold product being presented to the Spinning Blade.
    On the Video where the inventor demonstrates the SawStop he dips his hand a basin of cold water (and it is from memory quoted as being cold salted water) before presenting his finger to the blade.

    Why is a room temperature frankfurt not used.

    What happens if one has dry skin will the device still activate and has it been demonstrated to do so?

    I would suggest that it is unusual for the average woodworker to have hands/fingers that replicate a damp/slimy frankfurt.

    Looking forward to your comment
    Macn

  2. CGH

    Just because some of you are perfect…Accidents happen to all of us. Have you never tripped on a stair or something else. I wasn’t distracted, tired or using the saw irresponsible, but it got me.
    Sawstop asked other companies to license their stopping system. None of them wanted to protect the consumer.
    So some of you only want airbags in high end cars?
    This is what you are saying about the table saw industry and yes it takes going to “big brother” to get people (companies) to act responsibly.
    Sawstop isn’t necessarily asking for THEIR system to be put on all saws. Just some type of safety system. If no one can come up with something else, then yes they should be rewarded for their invention. Wouldn’t you want to be paid your rightful dues.
    We have all been taught, “safety first.” That should be at all costs.

  3. rbsrig

    The article by Robert Lang is most informative. I have no issue with the SawStop table saw accept for my opinion that it is inferior to the new Delta Unisaw that I purchased 3 months ago after having an INCA (with a riving knife) for more than 20 years, and after testing the SawStop and the newer Powermatic.
    As a woodworker with 50 years experience (I still have all of my fingers) and as an ordinary American, I am of the opinion that the Government or its agencies can’t legislate against stupidity. Is the table saw dangerous, YES. The fact that the people using the saw stop have more incidents than other folks gives credence to my opinion. The Government does have a obligation to protect the public, but what the SawStop people are asking for goes beyond that responsibility. They are asking the Government to increase their market share (at least for the short term).
    When I go to colleagues shops I almost never see a blade guard on their saws!
    People need protection from unscrupulous manufacturers of inherently unsafe products ( i.e. the automobile). If SawStop really cared about safety, they would license the technology to the other manufacturers say for a nominal fee of $10 or LESS, AND would advocate that the device be an OPTIONAL addition to their saws! I for one would not use it. My respect for my equipment is such that I never work when I am tired, under the weather or distracted.
    Robert L. Blum
    Robert L. Blum

  4. paulawest101

    There’s something inherently evil about a company that cries to Big Brother because “..nobody will license our invention”, so they demand Big Brother make the invention mandatory! Whether SawStop is a good product, or not is irrelevent. What matters is the whining designed purely to maximize profit. I for one find this reprehensibile.

  5. Shellac07

    Having spent years in the computer industry fighting Rambus another patent shop who is know for their predatory and ambitions to control the computer industry through their broad patents I am discussed that SawStop is now joining their ranks. It is way too easy to manipulate patents and amend them years after the original to keep competition at bay in order to garner large royalties.

    In general mechanical devices inherently have high failure rates as compared to electronic devices. Has anyone done a failure analysis of the SawStop device? I can not be guaranteed to work everytime; so what is the failure rate? Is it impervious to gum on the blade? I’m notorious for not keeping my blades squeaky clean. How well will this “flesh detecting” technology work if someone develops a non-conductive blade that is superior in cutting ability to today’s blades?

    Thanks for listening!

  6. measure twice

    I have had two tablesaws in my shop for a number of years. I use extra caution when using any powered machine and so far I’ve lost no body parts or blood. I was a machinest for 45 years and still have all my fingers. A SawStop machine would not change my habit of being very careful when using machinery. It would be a good “safety net” should I get lazy. However, the cost of a replacement blade/cartridge would keep me even more alert. My wife’s grandfather lost three fingers using his table saw some years ago. When she saw the SawStop demo at a woodworking show, she gave me permission to buy one, but, she didn’t give me the money..

  7. BRed

    While there seems to be a majority of “professional” woodworkers opposed to any SawStop-like technologies being required, I question the logic. I am an avid weekend woodworker and respect all tools in both safety operation and maintenance. I have never had a significant injury and can account that to careful observation to standard safety measures. However, just because I haven’t doesn’t mean no one else has or will –and that’s what this technology is about –protecting the entire group, not just the skilled within. This is akin to survival of the fittest when we are looking to grow our base, not scare it away with headlines like; “Toolmakers win battle against safety technology” –what kind of message does that send to the onlooker.

    As far as painting SawStop with the evil empire brush, let’s not forget that the founders begged the saw makers to adopt the technology long before going forward and launching their own saw. Had tool makers taken the technology seriously when it was introduces and viewed it as a means to help protect us, their users, they wouldn’t be lobbying so hard to stop the legislation today.

    Full disclosure; Yes, I am a SawStop owner; wife liked it and I liked the #1 position in the quality ratings.

  8. Recruiter

    My big concern with the possible decision by the CPSC, to require “flesh detecting technology” on all tablesaws is, SawStop is going to suddenly throw in lawsuits, on every company trying to develope their own technology, citing patent infringement. From what I understand, their patent is very broad based, leaving a lot up for interpretation. In order for a machinery company to not infringe on SawStop’s patent, it needs to come up with an entirely new concept, and then hope the courts don’t interpret even that as a conceptual infringement. That could take years, and probably million of dollars.
    IMHO, I think SawStop needs to get off their high horse, and allow the industry to grow. They feel they have the choke hold on the technology, and currently they do. Where would we all be today, if Michael Farraday, inventer of the first electric motor, didn’t allow his invention to be used and developed by anyone but himself. None of us would have a motorized tablesaw to work on – period.
    Dave

    1. Lee

      Hi Dave,

      A patent need only be 20% different to be authorized as a new patent for another company. Broad based means very little. The mechanics of the patent will be the deciding factor.

      Lee

  9. chucksdust

    You have to be smarter than the equipment. I am not saying SawStop is a bad thing, but it is no excuse for knowing how to use equipment in a safe manner. Flesh detecting technology is no excuse for pure laziness. The problem with most people today is a refusal to take responsibility for their own actions. If you can’t use equipment responsibly and properly then don’t use it at all and save the rest of us who do the hassle.

    1. rnewton43

      I agree 100% with chuck I have been a professional cabinet maker and trim carpenter for 20+ years. I have my own Delta table saws and a DeWalt job site table saw. None of the saws in my possession have guards on them. I rip boards down to 1 inch and don’t use a push stick, I still have all my fingers and fingernails and have never even had a scratch from blade contact. In those 20+ years I have only had 1 board kick back on me, painful?, yes but no damage done. Just BE AWARE of what you are doing LOOK at where things are….. I am very aware of what I am doing, if I feel the saw start to vibrate a bit I slow down my feed rate, I take extra time when sawing through knots or big shifts in the grain patterns. I keep my saws in a high state of tune and do maintenance religiously my blades are always clean and razor sharp.

  10. dreamcatcher

    “… SawStop owners make contact with the blade about three times as often as users of other saws…”

    Anyone who has followed my rants concerning SawStop technology would know that I already predicted this finding; just go to the SawStop website and you can read testimonials from happy idiots who couldn’t keep their hands out of their saw blades. I am glad they had the right saw to complement their incompetence but their could come a day that they find themselves ‘out of their element’ – say working in a friend’s shop or helping a buddy on a job and using a benchtop saw.

    I think that my hope concerning the regulation of this matter is that either the tool manufacturers around the world do some inventing of their own that puts [overpriced] SawStop tech to shame or that the guv’ment over-steps SawStop’s patent rights… ‘for the good of society’ of course. Anything to thwart the propaganda and corporate extortion that is being touted by Mr. Gass.

    DC

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