Spring and summer are popular times for homeowners to make improvements to their property. Perhaps you're looking to install some built-in shelves, or construct a back deck. Many of these projects will require you to spend long hours hammering nails before the feature is complete.

Nail guns are one way to speed up this work. This tool uses compressed air or a similar explosive force to fire a nail, easily securing materials such as wood, shingles, or siding. Nail guns allow you to complete these tasks, and therefore the entire project, more quickly.

However, this powerful tool can also cause serious injuries or death if it is not used properly. According to the Centers for Disease Control and Prevention, nail gun injuries result in approximately 37,000 emergency room visits each year. Construction workers make up about 60 percent of these injuries, but inexperienced homeowners can also find themselves in the ER if they aren't careful.

Nail gun operation

Nail guns have a trigger to fire the nail and a contact safety tip which must be depressed before the nail is fired. The Occupational Safety and Health Administration says all nail guns have these basic features, but that trigger mechanisms vary.

Contact trigger mechanisms allow you to fire a nail whenever the trigger or contact safety tip are both depressed. You can press the tip to a surface and pull the trigger, or you can pull the trigger and then press the tip to a surface. This design allows you to do "bump" or "bounce" nailing, since you can keep the trigger depressed and move the tool along a surface, pressing it down whenever you need to fire a nail.

Sequential trigger nail guns need to be activated in a certain way. You must first press the contact safety tip to a surface, then fire the trigger. Some designs require both trigger mechanisms to be released before you can fire another nail; others only require you to release the trigger, allowing you to keep the tip depressed and move the tool along the surface before firing again.

While nail guns with contact trigger mechanisms allow you to quickly move over a surface, they are also more likely to cause injury by firing a nail when you don't intend to do so. The Center for Construction Research and Training, an organization promoting safe work practices in the construction industry, says contact trigger mechanisms also do not result in a significant increase in productivity over sequential trigger mechanisms.

How nail gun injuries occur

Nail guns can fire a 10-centimeter nail at a speed of about 1,400 feet per second. This velocity, comparable to that of a rifle shot, is enough to fire the nail into concrete. As such, the nail can easily go deep into flesh if it is fired accidentally.

Many nail gun injuries result from an accidental discharge. OSHA says the tool might misfire when a person tries to place it against a surface. A person can also discharge the nail gun if they carry it with the trigger depressed and unintentionally place it against a surface or a body part.

Nails can react unexpectedly if you try to fire them into an unyielding surface such as metal, knots, or dense materials like laminated wood. Rather than going into this surface, the nail can ricochet or shatter, sending the nail or fragments into the air.

If you miss the underlying surface when firing a nail, it can become a projectile. For example, you might use a nail gun to attach plywood to a stud. If the nail misses the stud, it can easily punch through the plywood and go flying, injuring anyone in its path. You can also injure yourself if you need to hold a piece of building material in place while firing a nail, since you might misfire after the recoil or send a nail through the building material and into your hand.

You are more at risk for injury if you need to be in an awkward position to fire a nail. OSHA says these situations include standing on a ladder, firing a nail when the tip of the nail gun is not flush against a surface, using the nail gun above shoulder height, using your non-dominant hand to operate the nail gun, or using the tool in tight quarters.

Most nail gun injuries are a result of inexperience, unsafe handling, or a lack of safety features on the tool. The hand is the most commonly injured body part, since a person can easily put it in the path of the nail gun by mistake.

Nail guns typically cause soft tissue damage, but are also powerful enough to fracture bones. They can cause serious injuries or death if the nail pierces the eye, skull, or internal organs.

Nail gun injuries can easily become infected, since the projectile can draw foreign materials into the wound. Since pieces of copper wire are used to create strips of nails to be used in nail guns, barbs of this wire might stay on the nail; if the nail enters flesh, these barbs will make it harder to remove.

Staying safe

OSHA recommends using a nail gun with a sequential trigger mechanism to reduce your chances of injury. This type of nail gun will only fire when the contact safety tip is depressed.

Be responsible when carrying a nail gun. Keep your finger off the trigger when taking the tool to a new location. Don't use the compressed air hose to pull the nail gun to you or lower it to the ground.

Never bypass the safety mechanisms on a nail gun. Making modifications such as removing the spring from the contact safety tip will significantly increase the chances that a nail will fire unintentionally.

The compressed air used in the tool can also be hazardous. The hose can cause injuries if it becomes disconnected, and compressed air can unexpectedly eject nails. Disconnect the compressed air when you need to perform any maintenance on the nail gun, including clearing jammed nails. You should also take this step when passing the tool to another person, carrying it up a ladder, or leaving it unattended.

Wear protective equipment when using a nail gun. Eye protection and hard hats can help keep discharged nails from causing serious injury. Since the tool is especially loud, earplugs will protect against hearing loss.

Never fire a nail gun toward yourself or anyone else working with you. Make sure no one is present behind a surface nails may be able to punch through.

When placing material that needs to be nailed, keep your hands at least 12 inches away from where you are firing the nail. For some work, you might want to secure the material with clamps.

Look for any knots, fasteners, or other obstacles which might cause a nail to ricochet or shatter. Avoid firing nails in these areas.

Take the time to read the manufacturer's manual and instructions. You can also look for a training session in your area to receive detailed instructions on how to use the nail gun and avoid hazards.

If the tool is not working properly, do not continue to use it. The safety features may not work in a defective nail gun, making it more likely that a nail will be fired accidentally and cause injury.

In some areas, it is best to rely on a hammer. It is safer to use a hammer when attaching metal fasteners or working in a place where you cannot comfortably use a nail gun.