First NIOSH Comic Helps Dispel Internet “Myth”

Posted on by Jim Albers, MPH, CIH; Brian Lowe, PhD, CPE; Stephen Hudock, PhD, CSP

 

In June, we released the first-ever NIOSH comic Straight Talk About Nail Gun Safety. The comic has been well received by organizations and stakeholders  interested in increasing awareness and prevention of injuries resulting from nail gun use.  In the publication we described (p 1, panel 3) the pneumatic nail gun (PNG) velocity, 150 ft/sec, at the upper end of the range reported by two investigations that conducted tests to measure pneumatic nail gun velocity – the Consumer Product Safety Commission[1]  and the late Boulter Kelsey[2], a forensic engineer.  We received an inquiry  suggesting that 150 ft/sec understates the power of these tools and referenced a velocity nearly 10 times higher (1400 ft/sec).  We were confident in our data and knew that even at lower velocities, nail guns can cause serious injury, but we were curious:  How could such widely varying data exist in the scientific literature?  We were on the case. 

Initially, we were directed  to an article published on the “How Stuff Works” web site entry about nail guns (How Nail Guns Work) which stated:  “Just like a handgun, power nailers fire projectiles at high speed — some designs launch nails at speeds reaching 1,400 feet per second (427 meters per second).” [3] No citation was provided for the velocity value.

When we turned to Google to find the original source, we ended up with 21,000 ‘hits’ by using “nail gun” and “1400 feet per second” as search terms.  Most sites that appeared immediately were legal or medical, though they quickly digressed to include ‘theatrical’, paranormal, and vampire-hunting (using silver nails, we presume) interests.  Narrowing the search to “scholarly” sources, we found several peer reviewed papers that referenced a nail firing velocity of 1400 ft/sec and others that reported different velocities.  (Just to note, no articles were found using these search terms in PubMed or MedLine). All articles except one were medical journal case reports of nail gun injuries. The oldest and most frequently cited paper was from 1983, but this paper did not provide or reference an actual velocity measurement.[4]

The article we found that specifically cited the 1,400 ft/sec velocity value was written in 1997[5]. The earlier paper it referenced[6], however, did not report a specific nail gun velocity and instead alluded to the “driving force of the pin was the explosion of a .22-caliber (10mm) cartridge.”  While .22 caliber cartridges have variable velocities, some long-rifle .22-caliber cartridges are reported to include velocities in the 1400 ft/sec range.  The second article[7] describing specific velocities stated that “nail guns must be used with caution as they are capable of firing projectiles of up to 100 to 150 m/s and distances of up to 500 m.”  (Converted to ft/sec, these values are, respectively, 328 to 492 ft/sec). 

In 2001, a journal published a nail gun injury epidemiology article[8] based on an earlier report[9] that stated nail guns “can fire up to nine nails per second at velocities as high as 1,400 ft. per second.”  One year later an article was published[10] that included nail gun velocity data corresponding to measurements conducted by the CPSC [1] and Mr. Kelsey [2]. The data was collected by the authors themselves and reported they had “measured the velocity of experimentally fired nails with a ballistic chronograph … The velocity of the fired nails ranged from 97.7 to 121.1 ft/sec (mean: 105.5).”  Subsequent injury case reports in medical journals continued to reference varying ”nail gun” velocities, including 424 m/s (1391 ft/sec)[11] , 200 mph (293 ft/sec) [12]  and 293 ft/sec[13] .  Our “sleuthing” did find a 1975 reference in a medical journal that reported pneumatic nail gun muzzle velocities “being only 20 to 30 meters per second (66 – 98 ft/sec) 2 meters from the nailer muzzle.”[14]

How is it that so many different nail gun velocities were reported over so many years? The answer to this question appears straightforward.  Two types of fastening tools used in the construction industry to shoot fasteners into building materials have been called “nail guns”.  One tool uses an explosive charge and the other uses compressed air as energy sources to propel the fastener. The higher velocity tool is called a “powder actuated tool” (PAT)[15] and uses the explosive charge – often cordite – to propel the fastener.  The explosive charge is comparable to a .22-caliber ‘blank’. The resulting velocity, ranging from 315 ft/sec (96 m/s) to 1,295 ft/sec (395 m/s) [14] depends on the type of charge and whether the charge directly or indirectly propels the fastener.  Higher velocities produced in the PAT are used to drive fasteners into concrete or metal.

The far more common nail gun (or nailer) used to fasten lumber together uses compressed air to propel a piston to drive the nail into the lumber[16].  These are pneumatic nail guns (PNGs).  PNGs are not engineered to penetrate concrete or metal materials and operate at much lower velocities than the PAT.

Many early “nail gun” injury case reports that appeared in medical journals described injuries occurring with both PATs and PNGs and incorrectly assumed that the velocities were comparable or made no effort to describe the differences.  An article published in 1986 that described both types of tools stated that the “driving force for the pin was the explosion of a .22-caliber (10 mm) cartridge.”[6] Eleven years later an article describing two PNG injuries referred to nail guns “used to fire nails into steel, masonry and wood” and went on to describe the tool’s “velocities as high as 1,400 feet per second.”  This article not only confused the purpose of the two types of tools, but indirectly attributed the higher velocity capability of the PAT to the PNG.  This article was later cited in the nailer injury epidemiology report in 2001. [8] One year later an injury case report [10] included PNG velocity measurements conducted by the authors that confirmed those reported by the CPSC [1] and Kelsey [2].

The PAT and PNG energy difference appears to matter most when an airborne fastener strikes the body at a distance or when a shot at a close distance strikes bone.  In each case the PAT propels the fastener with greater velocity, kinetic energy, and potential to cause a disabling or even fatal injury.  This is illustrated in the Discovery Channel television program “Mythbusters” that compared the penetration capacity of an airborne projectile shot from a pneumatic framing nail gun to that of a 9mm hand gun.   Though its intent is entertainment rather than scientific study, the “Mythbusters” segment demonstrates quite clearly that pneumatic nail guns do not have the equivalent muzzle velocity of a hand gun or a PAT.

Regardless of the lower velocity, pneumatic nail guns are dangerous tools.   Deaths and seriously disabling injuries have occurred when fasteners were shot from a pneumatic nail gun with immediate contact to the head, chest, or torso. It is in the pneumatic nail gun user’s best interest to handle these tools as if they were a firearm despite having a lower velocity.  We have provided a list of  resources below  that provide nail gun safety information.  There is no “myth” in stating that pneumatic nail guns can result in serious injury or even death.

Jim Albers, MPH, CIH; Brian Lowe, PhD, CPE; Stephen Hudock, PhD, CSP

NIOSH Organizational Science & Human Factors Branch, Division of Applied Research and Technology, Cincinnati, OH

Special thanks to Kathy Connick, Librarian, OSELS, who assisted our publication search.

Resources

Straight Talk About Nail Gun Safety 

Plática directa sobre seguridad con pistolas de clavos 

Nail Gun Safety: A Guide for Construction Contractors 

Seguridad con las pistolas de clavos: Guía para los contratistas del sector de la construcción

Nail Gun Safety: The Facts  (CPWR)


[1] Consumer Products Safety Commission (CPSC), [2002]. Evaluation of Pneumatic Nailers. Memo from Carolene Paul to Jacqueline Elder. May 23, 2002. See http://www.cpsc.gov/library/foia/foia02/os/nailers.pdf.

[2] Kelsey, H.B. (2000) Additional Information for Forensic Engineers Regarding Nail Guns.  Journal of the National Academy of Forensic Engineers, December, 2000.

[3] Harris T. How Nail Guns Work. Accessed June 27, 2013. http://home.howstuffworks.com/nail-gun4.htm.

[4] Lyons FR. Industrial nail gun injuries. Med J Australia. 1983;2(10): 483–487.

[5] Hoffman DR, Jebson, PJL, Steyers, CM (1997) Nail Gun Injuries of the Hand. Am Fam Phys, Oct, 15, 1997 1643-1646.

[6] Edlich RF, Silloway KA, Rodeheaver GT, Morgan RF, Birk K, Thacker JG. Industrial nail gun injuries. Compr Ther. 1986;12:42–6.

[7] Beaver AC, Cheatem ML. Life threatening nail gun injuries. Am Surg 1999;65(12)192-5.

[8] Baggs J, Cohen M, Kalat J, Silverstein B. (2001) Pneumatic Nailer Injuries: A Report on Washinton State 1990-1998. Occupational Safety, Jan 2001 1:33-38.

[9] Baggs J, Kalat J, Cohen M, Silverstein B. (1999) Pneumatic Nailer (“Nail Gun”) Injuries in Washington State, 1990-1998

Technical Report Number:59-1-1999. Safety and Health Assessment and Research for Prevention (SHARP) Program

Washington State Department of Labor and Industries.

[10] Buchalter GM, Johnson LP, Reichman MV, et al. Penetrating trauma to the head and neck from a nail gun: A unique mechanism of injury. Ear Nose Throat J. 2002;81:779-783.

[11] Nizam I, Choong PFM. The nail gun: injuries to the knee and chest. Injury, Int J. Care Injured 34 (2003) 240-41.

[12] Horne BR, Corley FG. Review of 88 nail gun injuries to the extremities. Injury, Int J. Care Injured (2008) 39, 357-361.

[13] Rhee PC, Fox TJ, Kakar S. Nail gun injuries to the hand. J Hand Surg Am. 2013 Jun;38(6):1242-6. Epub 2013 Mar 28.

[14] Peterson CA, Dixon GL (1975) Pneumatic Injuries to the Bone, Letters to the Editor, Clinical Orthopaedics and related Research, No. 10, July-August, 1975, 334-6.

[15] Wikipedia (2013) Powder-actuated tool. Accessed June 28, 2013. http://en.wikipedia.org/wiki/Powder-actuated_tool

[16] Nail gun. Wikipedia. Accessed June 28, 2013. http://en.wikipedia.org/wiki/Nail_gun

Posted on by Jim Albers, MPH, CIH; Brian Lowe, PhD, CPE; Stephen Hudock, PhD, CSP

43 comments on “First NIOSH Comic Helps Dispel Internet “Myth””

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    I agree with the authors that pneumatic nail guns can be a dangerous tool on the wrong hands. With that said, much of the danger depends on the size of the nail being driven. It takes much more force to drive a 3″ framing nail then it does a 1″ finishing nail or brad. Also, many roofing contractors use their pneumatic nailers in an auto mode where the trigger is locked open so all that’s necessary to shoot a nail is to tap the gun on the roof. This is done primarily for speed but if in that mode if the nail gun would hit a leg or foot, it will still discharge. I’ve seen framing nailers set to the same auto mode. It’s not too difficult to bypass the safety mechanisms on these nailers which should also be mentioned on documents. Such as do not bypass the manufacturer’s trigger safety interlock.

    Our focus at NIOSH has been on the framing nail gun used in building construction, especially home building, which Joe Burkhart correctly identifies as potentially more hazardous due to the length of the fastener used.
    The comic we developed, as well as Nail Gun Safety – A Guide for Construction Contractors http://www.cdc.gov/niosh/docs/2011-202/pdfs/2011-202.pdf, does include warnings about disabling safety mechanisms.

    We know that nail guns can be dangerous even in the ‘right’ hands, especially when the contact trip actuation (aka bump or automatic) trigger is being used. Nails can be fired even when the operator never intended to do so when using the contact trip system, as Joe has described. This also increases risk of injury as a result of a ‘double fire’, which occurs when the gun recoils and makes contact with some body part and the finger is still on the trigger.

    A St. Louis carpenter clearly defined the safety issue regarding pneumatic nail guns with the following comment: “Nail guns might make (wood framing) easier, but all around it’s shooting a projectile at a high speed to go through hard materials. It’s just dangerous to work with.”

    Great idea to try out a comic. I look forward to hearing more about how it’s received, in the future!

    One interaction of the comic jumped out to me, starting the bottom of page 6.

    “Trainee: You said not to hold my finger on the trigger, but it’s heavy + there’s no other place for the trigger finger.

    Trainer: You’re right but…it’s still better than having your finger on the trigger. Otherwise you could injure yourself or a co-worker.”

    Not a criticism, because I know it’s still better not to do it: but this interaction stood out to me as not a great motivator, when the trainer’s just confirmed the gun is indeed heavy and harder to hold when you don’t let your finger fall to the natural trigger position.

    It also made me think, engineering-wise, it would be great if a nail gun could be designed to include a “rest spot” for the trigger finger, when carrying or preparing to use. Is there such a model out there?

    Thank you for your comment and we agree that engineering controls, when feasible, are preferred. In the focus groups we conducted while developing the document this issue was raised by workers and subcontractors alike.

    The pneumatic nail gun trigger has an affordance (a term used by Human Factors Psychologists) in its design for resting the finger on the trigger surface. This is desirable when the intent is to actuate the tool. However, when carrying the tool around the workplace it is unsafe to rest the finger on the trigger of the tool. Some triggers are actuated with as little as 1.9 lbs of finger force (CPSC report, 2002). Gripping and carrying the tool while resting the index finger on the trigger (applying no force with the finger), or keeping the index finger extended, requires that the other three fingers create all of the grip force. It is more natural to grip with all fingers – including the index finger on the trigger. We agree that while it is easy to tell a worker to “…keep your finger off the trigger”, this goes against the natural action afforded by the tool design – to grip with all fingers and apply force on the trigger surface with the index finger.

    The intent of the comic was to provide a credible account of the risks and actions workers/contractors could take to reduce traumatic injuries. To maintain this credibility we acknowledged the difficulty gripping some nail guns without depressing the trigger, though this may be regarded as less “motivational”. This difficulty was a concern we heard in many focus groups from workers and subcontractors alike. Some were able to take this concern a step further and suggest the need for some type of design change, such as the “finger rest” you suggested. (We are not aware of a pneumatic framing nail gun design with a dedicated finger rest.) Other stakeholders believed this provided additional justification for adopting the sequential actuation trigger – because it will not activate if the trigger is depressed before the nose makes contact with a surface.

    Nail guns can lead to manyaccidents if you are not careful which i must say are very well highlighted in the article. Great article.

    It is truly a nice and helpful piece of info. I am happy that you shared this helpful info with us. Please stay us informed like this. Thanks for sharing.
    sam

    I started in the construction industry in 1959, 55 years ago ( and I’m still working part time to keep the mind and body active) and in that time I have seen many changes including the move from the use of hand tools to electric and pneumatic power tools. Whatever the tool the simple fact remains the same, the user is responsible for his conduct and actions at all times. Trying to lay the blame and responsibility on to third parties (manufacturer, seller, employer) is a non starter. Every tool in my tool boxes is safe if handled properly and every tool is dangerous if not used properly. Injuries from nail guns in the construction industry are at the bottom end of the scale. You may legislate about instruction and training but you can never legislate against stupidity.
    I have only suffered one injury from a nail gun, back in 1984 when I shot a 15gauge finish nail through the index finger of my left hand. The nail gun was, according to some of the so called experts a “safe” nail gun because it had a sequential trigger. It was not the manufacturers fault, it was not the sellers fault and I had read all the safety instructions. I was clearly my own fault because I did not change the length of the nail for the application.

    All the talk about contact tips, sequential tips and triggers and nail gun design and safety is a smoke screen for deficiencies in the OSHA Act. If ALL construction workers, whether union workers, employees, day hire or subcontractors were made responsible and liable for their actions on a work site and not just the employer or principal contractor then that would be a start in preventing work place incidents ( I hate the incorrect descriptive word accident) On the spot fines for safety breaches by workplace safety and health inspectors would be would be a far better way to increase safety and safety awareness than any comic. The power by workplace safety and health inspectors to give on the spot fines for safety breaches has and is working well in a number of overseas countries in reducing workplace injuries and unsafe work practices.

    Just imagine the effect of injuring yourself with a nail gun by not operating it properly and getting hit with a $400 fine. I would have far more impact than any comic.

    I own and use pinners, finish nail guns, framing nail guns (stick and coil) decking and fencing coil nail guns, metal connector nail guns with both contact and sequential triggers and 3 way switchables. All of those nail guns are safe to use if used properly and if not used properly they are dangerous.

    Great article. I think the comics really made the article fun to read. I am just starting my blog and was looking for some good ideas to gain readers. I think I will try the comics. Thanks

    This is a pretty good article, but just being smart and using proper safety should be common sense when dealing with things like a nail gun. Pretty cool comic too.

    Feel free to use the images. We ask that you attribute them to NIOSH and link back to the blog so that your audience can participate in the nail gun safety discussion.

    we want to participate to share information useful and interesting to all readers .

    This information really useful and interesting……Thanks for sharing the nail gun safety using way…..:)

    I am new to this blog. But I have enjoyed your post and learned something new. Waiting for your next update.

    Importance of Proper Pneumatic Nail Gun Handling
    Nail guns have been an underrated form of hazard when in use. These pneumatic nail guns are easily purchased for personal use for basic construction and fixing up problems at home. They can easily be purchased at a hardware store, without much information about careful handling. However, one must not underestimate the use of having a nail gun, and mishandling it can dangerously hurt somebody. The nail gun can reach up to 1,400 feet per second, with some medical publications verifying this information. However, this information is not typically available, and does not come with warning on the packaging.
    Like many construction materials, pneumatic nail guns is considered a dangerous construction instrument, and should be handled and stored with much care.
    Thanks!
    Albert Mills

    I was very pleased to search out this web-site.I needed to thanks on your time for this glorious learn!! I positively having fun with every little little bit of it and I’ve you bookmarked to take a look at new stuff you blog post.

    When a newbie comes into using a nail gun. It is very important to know the system of the proper use of a nail gun. In my personal experience, many newbies are injured when he/she uses a nail gun for the first time.

    This is really helpful info ever. Both infographics are interesting and useful. I want to share your article on my social media.

    Keep up the awesome work.

    Nailguns can be very dangerous! In my line of work we take every precaution to make sure that my contractors are safe and following safety guidelines. Great post! Chris

    It is a wonderful article stating about the nail gun comic. It makes the work straight and easy for us. I enjoyed reading this article. You would get the best review over here and would suggest others too. I like how you have researched and presented these exact points so clearly.

    it is a dangerous tool. It seems to me that in American law it is necessary to make a grouping of tools, where such tools will be on the list of dangerous. They can be used by people of a certain age and so on

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