Nail Gun Safety: A Guide for Construction Contractors (OSHA/NIOSH 2011-202)

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   Nail Gun Safety

   • A Guide for Construction Contractors
   • TM
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   • NIOSH and OSHA thank the following for their support in developing this guidance: the members of OSHA’s Advisory Committee for Construction Safety and Health (ACCSH) who recommended that guidance be developed; Dr. Hester Lipscomb and her colleagues for her research findings used in the report; CPWR—The Center for Construction Research and Training for their support of nail gun research; Tom Trauger and Winchester Homes for providing access to residential job sites for the photos used in this guidance; and Javier Arias of the Hispanic Contractors Association De Tejas for helping us develop the Spanish language version.
   • Cover x-ray of a nail gun injury to the hand involving bony penetration requiring surgical removal. Courtesy of Stephan Mann, MD, MPH; Medical Director, CorpOHS.
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   Nail Gun Safety

   • A Guide for Construction Contractors
   • Department of Health and Human Services
   • Centers for Disease Control and Prevention
   • National Institute for Occupational Safety and Health
   • Department of Labor
   • Occupational Safety and Health Administration
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   Disclaimer

   • This document is in the public domain and may be freely copied or reprinted.
   • This guidance document is not a standard or regulation, and it creates no new legal obligations. It contains recommendations as well as descriptions of mandatory safety and health standards [and other regulatory requirements]. The recommendations are advisory in nature, informational in content, and are intended to assist employers in providing a safe and healthful workplace. The Occupational
   • Safety and Health Act requires employers to comply with safety and health standards and regulations promulgated by OSHA or by a state with an OSHA-approved state plan. In addition, the Act’s General
   • Duty Clause, Section 5(a)(1), requires employers to provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm.
   • Ordering Information
   • Contacting OSHA
   • To order additional copies of this publication, to get a list of other OSHA publications, to ask questions or to get more information, or to file a confidential complaint, contact OSHA at 1-800-321-OSHA (6742) or TTY: 1-877-889-5627 or go to www.osha.gov.
   • Contacting NIOSH
   • To receive documents or more information about occupational safety and health topics, please contact
   • NIOSH: 1-800-CDC-INFO (1-800-232-4636); TTY: 1-888-232-6348; e-mail: [email protected] or visit the
   • NIOSH web site at www.cdc.gov/niosh.
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   Executive Summary

   • Nail guns are used every day on many construction jobs—especially in residential construction. They boost productivity but also cause tens of thousands of painful injuries each year. Nail gun injuries are common—one study found that 2 out of 5 residential carpenter apprentices experienced a nail gun injury over a four-year period. When they do occur, these injuries are often not reported or given any medical treatment. Research has identified the risk factors that make nail gun injuries more likely to occur. The type of trigger system and the extent of training are important factors. The risk of a nail gun injury is twice as high when using a multi-shot contact trigger as when using a single-shot sequential trigger nailer.
   • This guidance is for residential home builders and construction contractors, subcontractors, and supervisors. NIOSH and OSHA developed this publication to give construction employers the information they need to prevent nail gun injuries. Types of triggers and key terms are described. The guidance highlights what is known about nail gun injuries, including the parts of the body most often injured and the types of severe injuries that have been reported. Common causes of nail gun injuries are discussed and six practical steps that contractors can take to prevent these injuries are described. These are:
   • 1) Use full sequential trigger nail guns;
   • 2) Provide training;
   • 3) Establish nail gun work procedures;
   • …
6. Page 6

   Table of Contents

   • Introduction … 1
   • What the Guidance Covers … 1
   • Know Your Triggers … 2
   • How do Nail Gun Injuries Happen? … 4
   • Six Steps to Nail Gun Safety … 6
   • Use the full sequential trigger
   • Provide training
   • Establish nail gun work procedures
   • Provide personal protective equipment
   • Encourage reporting and discussion of injuries and close calls
   • Provide first aid and medical treatment
   • A Word about Other Hazards … 10
   • Conclusion … 11
   • For Additional Information … 12
   • References and End Notes … 13
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   Introduction

   • Nail guns are powerful, easy to operate, and boost productivity for nailing tasks. They are also responsible for an estimated 37,000 emergency room visits each year. 1 Severe nail gun injuries have led to construction worker deaths.
   • Nail gun injuries are common in residential construction. About two-thirds of these injuries occur in framing and sheathing work. Injuries also often occur in roofing and exterior siding and finishing. 2
   • How likely are nail gun injuries? A study of apprentice carpenters found that:
   • 2 out of 5 were injured using a nail gun during their 4 years of training.
   • 1 out of 5 were injured twice.
   • 1 out of 10 were injured three or more times. 3
   • More than half of reported nail gun injuries are to the hand and fingers. 4 One-quarter of these hand injuries involve structural damage to tendons, joints, nerves, and bones. After hands, the next most often injured are the leg, knee, thigh, foot, and toes. Less common are injuries to the forearm or wrist, head and neck, and trunk. Serious nail gun injuries to the spinal cord, head, neck, eye, internal organs, and bones have been reported. Injuries have resulted in paralysis, blindness, brain damage, bone fractures, and death.
   • Worksite Story
   • A 26-year-old Idaho construction worker died following a nail gun accident in April 2007. He was framing a house when he slipped and fell. His finger was on the contact trigger of the nail gun he was using. …
   • …
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   Know Your Triggers

   • Illustrated terms
   • Nail gun safety starts with understanding the various trigger mechanisms. Here is what you need to know:
   • How triggers differ
   • All nailers rely on two basic controls: a finger trigger and a contact safety tip located on the nose of the gun. Trigger mechanisms can vary based on: 1) the order in which the controls are activated, and 2) whether the trigger can be held in the squeezed position to discharge multiple nails OR if it must be released and then squeezed again for each individual nail. Combining these variations gives four kinds of triggers. Some nail guns have a selective trigger switch which allows the user to choose among two or more trigger systems. Each trigger type is described below along with a summary of how the controls are activated.
   • Trigger
   • Full Sequential trigger
   • This is the safest type of nail gun trigger. This trigger will only fire a nail when the controls are activated in a certain order. First, the safety contact tip must be pushed into the work piece, then the user squeezes the trigger to discharge a nail. Both the safety contact tip and the trigger must be released and activated again to fire a second nail. Nails cannot be bump fired. Also known as single-shot trigger, restrictive trigger, or trigger fire mode.
   • Single nail:
   • Push safety contact, then squeeze trigger
   • Multiple nails:
   • Release both safety contact and trigger and repeat process
   • Contact safety tip
   • Contact trigger
   • …
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   Single Sequential trigger

   • Like the full sequential trigger, this trigger will only fire a nail when the controls are activated in a certain order. First, the safety contact tip must be pushed into the work piece. Then, the user squeezes the trigger to discharge a nail. To fire a second nail, only the trigger must be released. The safety contact tip can stay pressed into the work piece. Nails cannot be bump fired.
   • Single nail:
   • Push safety contact, then squeeze trigger
   • Multiple nails:
   • Release trigger, move tool, and squeeze trigger to fire additional nail
   • Single Actuation trigger
   • Like the contact trigger, this trigger will fire a single nail when the safety contact and trigger are activated in any order. A second nail can be fired by releasing the trigger, moving the tool and squeezing the trigger again without releasing the safety contact tip. Note that some manufacturers refer to these triggers as “single sequential triggers”, but they are different. The first nail can be bump fired with a single actuation trigger but not with a true single sequential trigger.
   • Push safety contact, squeeze trigger, or squeeze trigger, then push safety contact to fire
   • Other trigger terms
   • The International Staple, Nail and Tool Association (ISANTA) voluntary standard includes technical definitions for trigger “actuation systems”. Tool manufacturers have names for trigger modes such as “intermittent operation method” or “precision placement driving”. …
   • …
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    How do Nail Gun Injuries Happen?

    • Useful terms
    • Recoil is the rapid rebound or kickback after the nailer is fired.
    • A double fire occurs when a second nail unintentionally fires because the nailer re-contacted the work piece after recoil. It can also occur if the safety contact slips while the user is positioning the nail gun. Several tool manufacturers offer “anti-double fire” features for their nail guns.
    • You should know
    • Unintended nail discharge is a common source of injuries. A study of workers’ compensation records found that two-thirds of nail gun injury claims involved some type of unintended nail gun discharge or misfire. 6
    • Worksite Story
    • Two framers were working together to lay down and nail a subfloor. One framer was waiting and holding the nail gun with his finger on the contact trigger. The other framer was walking backwards toward him and dragging a sheet of plywood. The framer handling the plywood backed into the tip of the nail gun and was shot in the back. The nail nicked his kidney, but fortunately he recovered. As a result of this incident, the contractor switched to using only sequential triggers on framing nail guns. Co-workers can get injured if they bump into your contact trigger nail gun. You can prevent this by using a full sequential trigger.
    • There are seven major risk factors that can lead to a nail gun injury. Understanding them will help you to prevent injuries on your jobsites.
    • Unintended nail discharge from double fire.
    • Occurs with CONTACT triggers.
    • …
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    Illustrated terms

    • Nail ricochet after striking a hard surface or metal feature.
    • Occurs with ALL trigger types.
    • When a nail hits a hard surface, it has to change direction and it can bounce off the surface, becoming a projectile. Wood knots and metal framing hardware are common causes of ricochets. Problems have also been noted with ricochets when nailing into dense laminated beams. Ricochet nails can strike the worker or a co-worker to cause an injury.
    • Missing the work piece.
    • Injuries may occur when the tip of the nail gun does not make full contact with the work piece and the discharged nail becomes airborne. This can occur when nailing near the edge of a work piece, such as a plate. Positioning the safety contact is more difficult in these situations and sometimes the fired nail completely misses the lumber. Injuries have also occurred when a nail shot through plywood or oriented strand board sheeting missed a stud and became airborne.
    • Common nail gun grip with finger on trigger
    • Awkward position nailing.
    • Unintended discharges are a concern in awkward position work with CONTACT and SINGLE ACTUATION triggers.
    • Nailing in awkward positions where the tool and its recoil are more difficult to control may increase the risk of injury. These include toe-nailing, nailing above shoulder height, nailing in tight quarters, holding the nail gun with the non-dominant hand, nailing while on a ladder, or nailing when the user’s body is in the line of fire (nailing towards yourself). …
    • …
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    Six Steps to Nail Gun Safety

    • You should know
    • Studies of residential carpenters found that the overall risk of nail gun injury is twice as high when using contact trigger nail guns compared to using sequential trigger nail guns. 8
    • Note that the studies could not quantify injury risks associated with specific tasks; it is likely that some nailing tasks are more dangerous than others.
    • About 1 in 10 nail gun injuries happen to co-workers. 9 This is from either airborne (projectile) nails or bumping into a co-worker while carrying a contact trigger nail gun with the trigger squeezed.
    • A voluntary ANSI standard calls for all large pneumatic framing nailers manufactured after 2003 to be shipped with a sequential trigger. However, these may not always be FULL SEQUENTIAL triggers. Contractors may need to contact manufacturers or suppliers to purchase a FULL SEQUENTIAL trigger kit.
    • Worksite story
    • A carpenter apprentice on his first day ever using a nail gun injured his right leg. He was working on a step ladder and was in the process of lowering the nail gun to his side when the gun struck his leg and fired a nail into it. He had no training prior to using the nail gun. New worker training is important and should include hands-on skills.
    • ➊ Use the full sequential trigger
    • The full sequential trigger is always the safest trigger mechanism for the job. It reduces the risk of unintentional nail discharge and double fires—including injuries from bumping into co-workers.
    • …
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    • Worksite story
    • that training is provided in a manner that employees can understand. Here is a list of topics for training:
    • How nail guns work and how triggers differ.
    • Main causes of injuries – especially differences among types of triggers.
    • Instructions provided in manufacturer tool manuals and where the manual is kept.
    • Hands-on training with the actual nailers to be used on the job. This gives each employee an opportunity to handle the nailer and to get feedback on topics such as:
    • After his crews experienced many double fires and a related serious nail gun injury, a New Jersey contractor switched to using only sequential triggers. He believes he has eliminated the risk of double fire injuries and he estimates that the change has had only a slight impact on productivity—a few extra hours per house.
    • – How to load the nail gun
    • – How to operate the air compressor
    • – How to fire the nail gun
    • – How to hold lumber during placement work
    • – How to recognize and approach ricochet-prone work surfaces
    • – How to handle awkward position work (e.g., toe-nailing and work on ladders)
    • – How best to handle special risks associated with contact and single actuation triggers such as nail gun recoil and double fires. For example, coach new employees on how to minimize double fires by allowing the nail gun to recoil rather than continuing to push against the gun after it fires.
    • What to do when a nail gun malfunctions.
    • Training should also cover items covered in the following sections of the guidance…
    • …
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    You should know

    • Set up operations so that workers are not in the line of fire from nail guns being operated by co-workers.
    • Training is important: untrained workers are more likely to experience a nail gun injury than a trained worker. 12
    • Check lumber surfaces before nailing. Look for knots, nails, straps, hangers, etc. that could cause recoil or ricochet.
    • Training does not trump triggers: trained workers using contact triggers still have twice the overall risk of injury as trained workers using sequential triggers.
    • For placement work, keep hands at least 12 inches away from the nailing point at all times. Consider using clamps to brace instead of your hands.
    • Use a hammer or positive placement nailer when nailing metal joinery or irregular lumber.
    • Always shoot nail guns away from your body and away from co-workers.
    • Always disconnect the compressed air when:
    • – Leaving a nailer unattended;
    • – Travelling up and down a ladder or stairs;
    • – Passing the nail gun to a co-worker;
    • – Clearing jammed nails;
    • – Performing any other maintenance on the nail gun.
    • Recognize the dangers of awkward position work and provide extra time and precautions:
    • – Use a hammer if you cannot reach the work while holding the nailer with your dominant hand.
    • – Use a hammer or reposition for work at face or head height. Recoil is more difficult to control and could be dangerous.
    • – Use a hammer or full sequential trigger nailer when working in a tight space. Recoil is more difficult to control and double fires…
    • …
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    • – Maintain three points of contact with the ladder at all times to prevent a fall—this means that clamps may need to be used for placement work. Holding a nailer in one hand and the work piece with the other provides only two points of contact (your feet). Reaching and recoil can make you lose your balance and fall. Falls, especially with contact trigger nailers, can result in nail gun injuries.
    • Don’ts…
    • Never bypass or disable nail gun safety features. This is strictly prohibited. Tampering includes removing the spring from the safety-contact tip and/or tying down, taping or otherwise securing the trigger so it does not need to be pressed. Tampering increases the chance that the nail gun will fire unintentionally both for the current user and anyone else who may use the nail gun. Nail gun manufacturers strongly recommend against tampering and OSHA requires that tools be maintained in a safe condition. There is NO legitimate reason to modify or disable a nail gun safety device.
    • Encourage your workers to keep their fingers off the trigger when holding or carrying a nail gun. If this is not natural, workers should use a full sequential nail gun or set down the nailer until they begin to nail again.
    • Never lower the nail gun from above or drag the tool by the hose. If the nail-gun hose gets caught on something, don’t pull on the hose. Go find the problem and release the hose.
    • Never use the nailer with the non-dominant hand.
    • ➍ Provide Personal Protective Equipment (PPE)
    • …
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    A Word about Other Hazards

    • Worksite Story
    • ➏ Provide first aid and medical treatment
    • A construction worker accidentally drove a 16 penny framing nail into his thigh. It didn’t bleed much and he didn’t seek medical care. He removed the nail himself. Three days later he felt a snap in his leg and severe pain. In the emergency room, doctors removed a sheared off nail and found that his thigh bone had fractured. Not all injuries are immediately visible. Failure to seek medical care can result in complications and more serious injuries.
    • Employers and workers should seek medical attention immediately after nail gun injuries, even for hand injuries that appear to be minimal. Studies suggest that 1 out of 4 nail gun hand injuries can involve some type of structural damage such as bone fracture. 13 Materials such as nail strip glue or plastic or even clothing can get embedded in the injury and lead to infection. Barbs on the nail can cause secondary injury if the nail is removed incorrectly. These complications can be avoided by having workers seek immediate medical care.
    • Air pressure. Pneumatic tools and compressor use are regulated under OSHA’s Construction standard at 29 CFR 1926.302(b). The provisions in this standard that are relevant for nail guns are provided below.
    • (1) Pneumatic power tools shall be secured to the hose or whip by some positive means to prevent the tool from becoming accidentally disconnected.
    • …
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    • and ensure that they are worn correctly. Employers should also ask about noise levels when buying nail guns—studies have identified ways to reduce nail gun noise and some manufacturers may incorporate noise reduction features.
    • Note: OSHA’s standard for exposure to continuous noise levels (29 CFR 1926.52) addresses both the noise level and the duration of exposure. In this standard, workers exposed for 15 minutes at 115 A-weighted decibels (dBA) have the same exposure as workers exposed for 8 hours at 90 dBA.
    • The NIOSH and OSHA limit for impulse noise is 140 decibels: above this level a single exposure can cause instant damage to the ear.
    • NIOSH recommends that an 8-hour exposure should not exceed 85 dBA and a one-second exposure should not exceed 130 dBA without using hearing protection.
    • Musculoskeletal disorders. Framing nail guns can weigh up to 8 pounds and many framing jobs require workers to hold and use these guns for long periods of time in awkward hand/arm postures. Holding an 8-pound weight for long periods of time can lead to musculoskeletal symptoms such as soreness or ten-derness in the fingers, wrist, or forearm tendons or muscles. These symptoms can progress to pain, or in the most severe cases, inability to work. No studies have shown that one trigger type is any more or less likely to cause musculoskeletal problems from long periods of nail gun use. …
    • …
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    For Additional Information

    • OSHA
    • Woodworking eTool—Handheld Nail/Stapling Guns www.osha.gov/SLTC/etools/woodworking/production_handheldstaplegun.html
    • Center for Construction Research and Training (CPWR)
    • Nail Gun Hazard Alert
    • www.cpwr.com/hazpdfs/Nail%20Gun%20Safety%202pg%20flier%20FINAL.pdf
    • Nail Gun Injuries, Productivity, and Recommendations www.elcosh.org/en/document/1160/d001056/nail-guns%253A-injuries%252C-productivity-and-recommendations.html
    • International Staple, Nail and Tool Association (ISANTA)
    • American National Standard SNT-101-2002—Safety Requirements for Portable, Compressed-Air-Actuated Fastener Driving Tools.
    • Home Page www.isanta.org/
    • Oregon OSHA
    • Pneumatic Nail and Staple Gun Safety Hazard Alert www.orosha.org/pdf/hazards/2993-21.pdf
    • California OSHA
    • Pneumatically Driven Nailers and Staplers CCR Title 8, Section 1704 www.dir.ca.gov/Title8/1704.html
    • Nail gun video materials
    • WorkSafe British Columbia—Nail Gun Safety, and Safe Handling of Nail Guns www2.worksafebc.com/Publications/Multimedia/Videos.asp?ReportID=35773
    • Unsafe Handling of Nail Guns. Case study and video www.speakingofsafety.ca/2011/04/28/unsafe-handling-of-nail-guns/
    • Sacramento Bee—Nail Gun Safety www.youtube.com/watch?v=MsCu9luSRRY&feature=related
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    References and Endnotes

    • 68% of these emergency room visits involved workers and 32% involved consumers. From: Lipscomb H, Jackson L [2007]. Nail-Gun Injuries treated in Emergency Departments—United States, 2001-2005. MMWR 56(14):329-332.
    • Dement J, Lipscomb H, Leiming L, Epling C, Desai, T [2003]. Nail Gun Injuries among Construction Workers. Appl Occup Environ Hyg 18(5):374-383.
    • Lipscomb H, Dement J, Nolan J, Patterson D. [2006]. Nail Gun Injuries in Apprentice Carpenters: Risk Factors and Control Measures. Am J Ind Med 49:505-513.
    • Lipscomb H, Nolan J, Patterson D, Dement D [2010]. Surveillance of Nail Gun Injuries by Journeyman Carpenters provides important Insight into Experiences of Apprentices. New Solutions 20(1) 95-114. Also, Baggs J, Cohen M, Kalat J, Silverstein, B [2001]. Pneumatic Nailer Injuries—A Report on Washington State 1990-1998. Prof Saf Mag January: 3V-38.
    • 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.
    • American National Standard Institute (ANSI) [2002]. Safety Requirements for Portable, Compressed-Air-Actuated Fastener Driving Tools. ANSI SNT-101-2002 Sections 4.4: Tools shall not be modified or altered; 8.4.2.3: Improperly functioning tools must not be used; 8.4.2.5.1: Do not remove, tamper with, or otherwise cause the tool operating controls to become inoperable.
    • …
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    Contacting NIOSH

    • To receive documents or more information about occupational safety and health topics, please contact NIOSH:
    • 1-800-CDC-INFO (1-800-232-4636); TTY: 1-888-232-6348;
    • e-mail: [email protected] or visit the NIOSH web site at www.cdc.gov/niosh.
    • Contacting OSHA
    • To order additional copies of this publication, to get a list of other OSHA publications, to ask questions or to get more information, or to file a confidential complaint, contact OSHA at 1-800-321-OSHA (6742) or TTY: 1-877-889-5627 or go to www.osha.gov.
    • DHHS (NIOSH) Publication Number 2011-202 | OSHA Publication Number 3459-8-11