How Do Nail Gun Injuries Happen
Are you aware of the potential dangers when working with power tools? Many people assume using a nail gun is safe, but its powerful force and various elements can cause serious injuries — even fatalities. From setting nails at an improper angle or misfiring floors and walls, there are many ways for these devices to be mishandled. So how do nail gun injuries occur exactly? This blog post will examine some factors leading to user error and potentially deadly results.
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. 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.
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 four years of training.
- 1 out of 5 was injured twice.
- 1 out of 10 was injured three or more times.
More than half of reported nail gun injuries are to the hand and fingers. 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.
How do Nail Gun Injuries Happen?
Seven major risk factors can lead to a nail gun injury. Understanding them will help you to prevent injuries on your job sites.
1. Unintended Nail Discharge From Double Fire.
The Consumer Product Safety Commission (CPSC) found that contact trigger nailers are susceptible to double firing, especially when accurately placing the nailer against the workpiece. They found that a second unintended firing can happen faster than the user can react and release the trigger. Unintended nails can cause injuries.
Double fire can be a problem for new workers who may push hard on the tool to compensate for recoil. It can also occur when the user is working in an awkward position, such as in tight spaces where the gun doesn’t have enough space to recoil. The gun’s recoil can even cause a non-nail injury in tight spaces if the nail gun hits the user’s head or face.
2. Unintended Nail Discharge From Knocking The Safety Contact With The Trigger Squeezed.
Nail guns with contact and single-actuation triggers will fire if the trigger is squeezed and the safety contact tip gets knocked or pushed into an object or person by mistake. For example, a framer might knock his leg going down a ladder or bump into a co-worker passing through a doorway. Contact trigger nailers can release multiple nails, and single actuation trigger nailers can release a single nail to cause injury.
Holding or carrying contact triggers or single-actuation trigger nail guns with the trigger squeezed increases the risk of unintended nail discharge. Construction workers tend to keep a finger on the trigger because holding and carrying an 8-pound nail gun is more natural using a full, four-finger grip. Tool manufacturers, however, do warn against it.
3. Nail Penetration Through Lumber Work Piece.
Nails can pass through a workpiece, hit the worker’s hand, or fly off as a projectile (airborne) nail. A blow-out nail is one example. Blow-outs can occur when a nail is placed near a knot in the wood. Knots involve a change in wood grain, which creates both weak spots and hard spots that can make the nail change direction and exit the workpiece.
Nail penetration is especially a concern for placement work where a piece of lumber must be held by hand. If the nail misses or breaks through the lumber, the nondominant hand holding it can injure it.
4. Nail Ricochet After Striking A Hard Surface Or Metal Feature.
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.
5. Missing The Work Piece.
Injuries may occur when the tip of the nail gun does not make full contact with the workpiece, and the discharged nail becomes airborne. This can occur when nailing near the edge of a workpiece, 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.
6. Awkward Position Nailing.
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 line fire (nailing towards yourself).
Toe-nailing is awkward because the gun cannot be held flush against the workpiece. Nailing from a ladder makes it difficult to position the nail gun accurately. Nailing beyond a comfortable reach distance from a ladder, elevated work platform, or leading edge also puts the user at risk of falling.
7. Bypassing Safety Mechanisms.
Bypassing or disabling certain trigger or safety contact tip features is an important risk of injury. For example, removing the spring from the safety contact tip makes an unintended discharge even more likely. Modifying tools can lead to safety problems for anyone who uses the nail gun.
Nail gun manufacturers strongly recommend against bypassing safety features, and voluntary standards prohibit modifications or tampering. OSHA’s Construction standard at 29 CFR 1926.300(a) requires that all hand and power tools and similar equipment, whether furnished by the employer or the employee, be maintained in a safe condition.
8. Unexpected Recoil (Kickback).
Recoil, or kickback, occurs when the nail has enough force to push the gun backward toward the user. This can occur if a blockage in the tool prevents complete nailing and causes an unexpected reaction from the tool.
It also happens when nails are driven into hard surface material such as concrete. Recoil can cause the user to lose control of the nail gun, leading to unintended discharge and potential injury.
9. Extended Trigger Lock-On Time.
Nail guns are equipped with lock-on triggers that keep the tool firing when it is depressed for an extended period, usually several seconds or more. This could result in the unintended nailing of an object or person. This is another reason why it is important to have a good grip on the nail gun and avoid holding it with your non-dominant hand.
10. Accidental Drop Or Throw Of The Nail Gun.
Nail guns are heavy and awkward to handle, which can lead to unintentional dropping or throwing of the tool. When this happens, the nail gun could discharge and cause an injury to the user or a bystander. It is important always to keep the nail gun pointed away from yourself and others when you are carrying it.
In summary, there are many potential causes of nail gun injuries, including ricochet after striking a hard surface, missing the workpiece, awkward position nailing, bypassing safety mechanisms, unexpected recoil (kickback), extended trigger lock-on time, and accidental dropping or throwing of the tool. It is important to understand these hazards to use nail guns safely and avoid potential injuries. Additionally, it is important never to modify a nail gun or bypass its safety features, as this can increase the risk of injury.