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When It Comes to Construction Safety, What You Don't Know Can Hurt You

TJ Lyons | March 24, 2017

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Wooden ladder in construction trench

When construction safety managers walk their projects, their job is to point out things to make the site safer. That is a safety manager's gift to offer. One US safety professional says, "A safety professional is really a walking lesson learned." This column deals with some of those things good people do not know but must know.

I have not decided on a top-10 list yet, so here are my top four.

1. Metal Halide Light Bulbs

These cartoon-sized bulbs produce an intense and harsh light. Several "types" of the bulb are offered based on their use, fixture, placement, etc. In addition, they can burn your retinas. (That got your attention, right?)

Metal Halide Light

These bulbs became common on construction sites a decade or two ago, but they contain a unique and often unknown hazard. Their strong ultraviolet (UV) light is protected by an internal shield and, if that shield fails and the light still burns, it will burn your eyes and skin—not that you would be aware of it—not right away that is.

In one case, about 100 people were sent to a Washington hospital after one of these bulbs failed in a school gym when the UV shield broke but it continued to glow. Those short-wavelength UV light caused burns to the skin and eyes of those in the bleachers. The Food and Drug Administration (FDA) calls these a threat to public safety. 1


Type-R bulbs should never be used on a construction site. Type-S and type-O work, and type-T bulbs are better.

  • Unsure what type you have? Do not look at the bulb when it is on. Turn off the lamp and look. These bulbs are marked so you can check, or look at the replacements bulbs in storage. Turn the lamp back on, for a failed bulb will not relight.
  • If you're using type-R bulbs, then turn your lights on and off at each shift, and you can stay ahead of this hazard.
  • Use the new LED lamps that are now showing up on projects. They produce a wonderful light, and you can eliminate this threat.
  • Against the guidance of dear Sister Christine, my trick is to remember type "R" is wRong, "O" is OK, and "S" is safe.

2. Lattice-Boom Jib Extensions

I once got a call from a father asking about a crane accident I had investigated. The father owned a crane company and sent his son out to make a lift. The contractor had ordered too small of a crane (a common cost-saving mistake), so the son swung out the crane's lattice boom extension. These are often attached to the side of a mobile crane. (See the photo below.) Though useful for reaching any height, they have to be deployed by the operator. They swing around and are locked in. These extensions may fail and fall when the operator does that. In this case, the extension fell onto his son, breaking his hard hat, neck, both shoulders, and both hips. Somehow, he survived.

Lattice Extensions

Having been on the site during another similar failure, I had the chance to investigate that incident. Though no one was hurt (it landed 1 foot from the operator's foot), I traveled and met with one of our crane manufacturers about how this could happen and how to prevent it. Some of the contributors at the time were instruction manuals that detail how to deploy but often tell the operator to do those steps in reverse to store. Controls near or under the swinging extension put the operator under the load, and connections used during deployment, in my opinion, should have been designed differently.

Does this occur often? One of the leading US crane experts tipped me off to 89 cases related to these failures. A 2015 report related to crane fatalities in Australia "… reported the involvement of lattice-boom cranes in 93% of fatalities that were associated with assembly or dismantling…." 2


  • Consider deployment of these extensions as only a critical lift.
  • Keep personnel involved in the deployment—and those in the area—as far from the operations as possible.
  • Ensure your subcontractor sizes the correct crane so that the extensions are not required.

3. Lead in Powder Actuated Tools

Over 8,000 years ago, they built lead smelters in Europe. In the seventeenth century, lead exposure was linked to humans' "stomach cramps." Some experts blame the widespread use of lead for the fall of the Roman Empire, for they used lead for plumbing of their waterlines. Seemed like a great idea at the time, I am sure. "Plumbum" is Latin for lead.

In the early 1920s, lead was poisoning immigrants who were working by coating bathtubs in the United States. This practice was recognized by the mother of industrial hygiene, Alice Hamilton. A picture of her hangs over my desk and her autobiography, Exploring the Dangerous Trades, is a classic history of how we have hurt some nice people. Then, symptoms of lead poisoning were often attributed by company doctors to someone drinking or slothful lifestyle of immigrants—not the work they did. Consider one task was to take shovelfuls of white lead and throw that on cherry-red steel claw-foot bathtubs. One symptom of lead exposure was a drooping foot.

In the 1920s, someone determined that lead added to gasoline gave you more bang for your buck. That scientist, sadly, was severely injured by lead poisoning. Common in house paints until the 1970-1980s, we have eliminated that lead exposure here in the United States, though much lead-based paint remains on our buildings.

However, the use of lead continues in construction in roof flashing, X-ray rooms, and guns that shoot nails into concrete. Called powder-actuated tools, some of these have lead in the cartridge's primer. In a 2014 safety data sheet (several years after the study), lead is listed in the ingredients.

Table 1. 3. Composition/Information of Ingredients
Components % By Weight CAS Number EINECS/ELINCS #
Iron 0–97 7439-89-6 231-096-4
Copper 50–65 7440-50-8 231-159-6
Zinc 15–32 7440-66-6 231-175-3
Nitrocellulose 2–13 9004-70-0 Polymer
Nitroglycerin 0.5–2 55-63-0 200–240-8
Lead styphnate 0.1–1 15245-44-0 239-290-0

These guns look like a phaser from Star Trek and use bullets in a magazine to drive nails into hard surfaces like steel or concrete. Really, we do that.

Powder-Actuated Tool Magazine and Cartridge

I was made aware of this unique threat from a friend at the National Institute for Occupational Safety and Health when he asked if we still see these on construction sites. The answer is yes, we still do. He sent along some information on tests conducted by our friends in Canada at the Construction Safety Association of Ontario. The study was presented in 2010 at the American Industrial Hygiene Conference and Exposition and found a link between "lead exposure and explosive actuated tools." Let me know if you want a copy.


  • Use lead-free cartridges that are easily available.
  • Buy guns designed to use compressed gasses or other forces to drive the nail.
Gas Powered Nail Gun

4. Gas Powered Hand Saws—Chop or Demo Saws

More suitable for action scenes in Die Hard or The Walking Dead, or firefighters cutting holes in a burning roof, these orbital saws can kill. Picture a chainsaw with a round blade. However, unlike a chainsaw that stops when you let go of the trigger, these blades will spin unless stopped by gravity, a solid object, or your carotid artery.

Gas Powered Chop

Often, these tools are used overhead, so when they have a kickback, they may hit the worker in the neck. In other cases, workers are trimming pipe to fit in an excavation. They are working below their waist, so if the saw jumps, their femoral artery stops the blade. Having used these direct-drive saws, there is an inherent torque produced. These saws will try to twist their way out of your grip before you even use it. When it does have a kickback, those torque forces remain, making it harder to control. Add some dust or mud, wet gloves, poor footing, or need to work off of a ladder, and you have a disaster.

I am passionate about a few things in my safety life. One is discontinuing the use of most ladders, exits in airplanes with seats in the way, ridding the world of fork trucks designed where the operator cannot see to the right, and getting chop saw manufacturers to step up and fix this obvious hazard. I am now working with the Consumer Product Safety Commission in hopes of correcting this.

Are injuries or fatalities common? Around last Thanksgiving, such a saw killed a worker. Described in a November 24, 2016, Engineering News-Record article, "Worker Killed in Freak Chop-Saw Accident," as a "freak accident," in fact, this accident was foreseeable.

A 28-year-old water mechanic cutting a water-pipe connection to a Duxbury, Mass., residential construction died on Nov. 16, when his circular chop saw became bound and kicked back, striking him in the neck. [Emphasis added.]

Authorities have identified the dead man as Jason Sanderson of Carver, Mass. The office of Plymouth County District Attorney Timothy Cruz stated that Duxbury Police responded to a 2:15 p.m. report of a workplace accident on Tremont Street, where emergency personnel found Sanderson suffering from a severe neck wound. Paramedics administered first aid at the scene before Sanderson was rushed to Beth Israel Hospital, Plymouth, where he was pronounced dead.

These saws must be designed with a clutch or other mechanism like a chainsaw, so the blade will stop when the trigger is released, or the saw jumps unexpectedly.

For those in risk management, these are devices to watch. The good news is that one manufacturer will soon have a saw on the market that corrects some of the hazards. Like table saws and the use of technology to stop carpenters from losing fingers, I see technology used to save the lives of sons and daughters using these saws.


When I was 10, my dad sent my twin brother Frank and me into the septic tank on our farm to clean out the pumps. It was deep enough to require a ladder attached to the side to get down into it. We were small, so we fit and were able to do the job. We had no idea that such a tank kills those on farms every year.

The examples discussed in this article show some of the risks that workers face, risks they may not even be aware they are facing. With the upcoming National Safety Stand Down in May, consider using some of these examples to share with those doing construction work. Safety managers must shamelessly share what we know and have learned. Often, our first approach is to tell someone what he or she is doing is wrong. Please just take the time to help them understand why. Some folks just don't know.

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2 See Ehsan Gharaie, Helen Lingard, and Tracy Cooke, "Causes of Fatal Accidents Involving Cranes in the Australian Construction Industry," Construction Economics and Building, 2015.