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Objects falling from heights on construction sites lead to injuries

By Amanda Silliker
| www.cos-mag.com

Gary Anderson was delivering drywall to a construction site in New Jersey almost exactly one year ago. The independent contractor for a trucking company was leaning into a car window to speak with someone and, when he pulled his head out, he was struck by a tape measure and died. A worker on the 50th floor of the project was unfastening the 1-pound tape measure from his work belt when it slipped out of his hands, ricocheted off a piece of construction metal about 10 feet above the ground and hit Anderson.

Objects falling from heights are a huge safety concern. In 2013, there were 8,609 injuries from workers being struck by falling objects, and 23 were fatal, representing 2.5 per cent of all fatalities, according to the Association of Workers’ Compensation Boards of Canada.  Concussions, lacerations and puncture wounds are just some of the injuries that can ensue.

“I think it happens more frequently than people realize,” says Lou LeBlanc, owner of BuildSafe Construction Safety Services in Cambridge, Ont.

This issue is a particular concern in the construction industry and is easily among the top five hazards on any site, says Nate Bohmbach, senior project manager at Ergodyne in St. Paul, Minn. In the United States, struck by objects — which include objects falling from heights — are responsible for 10.1 per cent of deaths in the construction industry, according to the Bureau of Labor Statistics.

The types of objects that commonly fall are hand-held radios; hard hats; small tools, such as tape measures, wrenches and pliers; pieces of concrete; and nuts and bolts.

To determine what kind of force can be generated by an object falling from heights, calculations can be done around the physics of gravity. For example, an 8-pound wrench dropped 200 feet would hit with a force of 2,833 pounds per square inch (or the equivalent of a Clydesdale horse hitting a 1-square inch area).

“I even heard of a case where a blunt object hit somebody’s arm and it separated their shoulder,” says Bohmbach.

The shape of the object also determines the severity of the outcome. When a 2-pound hammer drops from 3 metres onto a hard hat, it won’t do very much; however, a 2-pound sleever bar (which looks like a long spike) dropped the same distance would punch through the hard hat and go into the skull.

In one case, a man was walking across a stadium field in Tampa, Fla., when ironworkers in the rafters dropped a spud wrench (a tool with a spike on one end and a wrench on the other) and it went through his shoulder and lung and into his stomach, recalls Mark Caldwell, director of fall protection for tools at Capital Safety, who is based in Woodstock, Ga.

“I was telling that story at a nuclear deconstruction site and this lady stood up and held up her shirt on her side… and you could see a scar about an inch and a half wide and she turned around and showed me the corresponding scar and said someone dropped a sleever bar and it hit a rail and came directly through her completely and she was out of work for two-and-a-half years,” says Caldwell.

While the most obvious person at risk when objects are dropped is the one underneath, the person using the item can be at risk as well.

“Let’s say a worker dropped their hammer. Their gut reaction is to try and snatch that hammer back before it ends up falling and that could throw somebody off balance,” says Bohmbach. “(Or) that dropped object could fall from a worker’s hand to the platform they are working on and a worker behind them could come by and trip over it.”

Aside from injuries to workers, dropped objects can cause other damages and incur additional costs for a company. The dropped object itself may be damaged or lost if it is dropped into water, mud, machinery, down hole or another difficult-to-reach place. 

Whatever the dropped object hits below will be damaged, ranging from the equipment, the structure itself or a parked car.

“Little bits of concrete the size of a whiteout bottle are falling off the edges (of buildings) quite frequently,” says LeBlanc. “This happens all the time and they just quietly pay for windshields and damage to vehicles. We don’t hear about it. It’s a cost of the job.”

Productivity can also take a hit, which is very difficult to measure.

“It could be lost time from investigating what happened. It could be running to Canadian Tire to get a tool that you broke when you dropped it. Or it could be up on 50th storey you dropped a tool you need to do a job and need to go all the way back down to get it and climb all the way back up,” says Bohmbach.

Public relations could be a cost if an incident makes the headlines, says LeBlanc. The employer may also accrue fines from the ministry of labour, as it is an employer’s duty to keep the workplace safe, which includes managing risks of dropped objects.

Harnesses for tools

One solution is tethered tools. These tools either have a built-in connection point placed by the manufacturer or can be retrofitted with connectors. Then, the tools are connected to a lanyard. Energy-absorbing lanyards will reduce the force associated with the dropped tool. Tools can either be connected to a worker through a tool belt, harness or wristband or anchored to a fixed structure.

As a general rule, a tool more than 5 pounds should never be tied-off to a person.

“You don’t take an 8-pound hammer and tie it to a body. What happens if I am swinging that hammer and it gets loose? At best, maybe it dislocates my wrist or shoulder. Worst case it pulls me over the scaffolding into a very bad situation,” says Caldwell.

If a worker has a tool attached to him and he needs to pass it to a colleague, the colleague can connect to the tool before the passing worker disconnects from it, ensuring the tool is 100 per cent tied off and never has the opportunity to become a drop hazard.

Employees need to be properly trained on how to use tethered tools. They must be taught how to attach the tools, use the lanyards properly and respect the weight rating of the lanyards.

Tethered tools are mostly seen among larger construction companies and are not widespread in the industry yet, says LeBlanc. But this could change with younger workers tending to be more inclined towards safety than the veterans.

“The younger crowd will take to it a lot quicker. (Other) workers will take to it; it just takes that habit. This is the new way. This is what we do now, even though I have never had a tool drop — and that’s where people need to be convinced,” says LeBlanc.

The site supervisor plays a big role as well, he says. For example, if the supervisor previously had a tool fall on a job and someone got hurt, he will be more diligent than if he has never had an issue in the past.

As a best practice, workers need to understand they should only bring up the tools they need to do their job. Unfortunately, that rarely happens, says Bohmbach.

“If they’re going up to a height, they’re more likely to bring every tool they have on the off chance they might need it, so they don’t need to climb back down and get it,” says Bohmbach. “We’d like to recommend them to carry as little on the body as possible to try and limit the amount of weight, because otherwise then you’re dealing with other issues like sprains and strains and fatigue.”

He recommends hoisting items up then transferring them over with various different lanyards either to the workers themselves (if necessary) or static anchor points. This can be done in a bucket, which can then house the extra tools. But the popular plastic buckets seen on many job sites come with safety concerns because they frequently fall over, spilling their contents.

“I’ve cited this before on my reports,” says LeBlanc. “You see an ironworker with a bucket of bolts up on a beam and if that falls over, anyone in the area is catching bolts coming down 20 feet, which could be deadly.”

There are many buckets, bags and pouches available on the market with closure systems so items do not fall out. Some even close automatically when turned upside down.

Another solution to  dropped objects is toe boards, required by many jurisdictions. For example, federal health and safety regulations require a toe board of at least 125 millimetres high “where there is a hazard that tools or other objects may fall onto a person from a platform or other raised area or through a floor opening or floor hole.”

Toe boards should be capable

of withstanding a force of at least

50 pounds in any downward or outward motion.

“People really underestimate the value of toe boards. It’s such a simple item; it’s a no-brainer,” says LeBlanc.

He recalls an incident back in the 1980s when a worker on a construction site placed his screwdriver and pliers on the edge of the floor. He had to leave the area and when he was coming back, another worker accidentally hit his tools and they came falling down. The screwdriver hit the worker’s hard hat and knocked it off, and the pliers came down immediately afterwards and squared him in the head.

“The mezzanine was only at 10 feet and the worker was 6 feet tall, so the tools fell only about 4 feet,” says LeBlanc. “The worker was in Niagara General (Hospital) for four months with a concussion that almost killed him. Had there been a toe board there, that accident wouldn’t have happened.”

Nets are another way to catch dropped objects. Green netting that goes over buildings when they are being refaced in cities or areas where there are a lot of pedestrians is the most well-known. There is also netting that is put up within the construction project, such as directly under work being done, to help stop objects from falling on workers underneath.

But nets can’t be the only solution because objects often don’t fall straight down.

“It’s kind of a myth that the only concern is directly below where the work is taking place,” says Bohmbach. “The reality is there is a deflection that can happen. When an object falls from the 20th storey and deflects off something on the 10th storey, that can fly hundreds of metres away and hit somebody that’s not even on the work site.”

A system where workers check tools in and out can also be effective, which is commonly used in oil and gas.

“(It’s about) making sure every tool that goes to height comes back down from height so that nothing is left

up there that could eventually

vibrate off and become a drop hazard,” says Bohmbach.

Construction workers need to be educated on the dangers of falling objects when working at heights. Safety professionals can increase awareness by putting up posters and making sure supervisors are discussing the issue in tool box talks. A best practice would be a dropped objects prevention guideline that outlines the risk of dropped objects, prevention strategies and responsibilities of managers, the health and safety committee and employees. For example, employees need to know they have a duty to report dangerous working conditions, such as a missing toe board.

“Besides, if a brick fell off because there was a missing toe board and someone got severely hurt and you knew about it before it happened… it would be hard to live with yourself and know you could have done something about it,” says LeBlanc.

One of the best ways to get buy-in from workers for dropped object prevention is to make sure they think about the people that can be affected by dropped objects.

“If my tool is on its way down, I yell ‘Watch out.’ Am I worried about my own personal safety at that point? Not at all. I’m worried about everyone else’s. That’s the key. The harness on your body is about you; the harness and lanyards on the tools aren’t about you, they’re about everybody else,” says Caldwell. “That cuts the whining out immediately. This makes you part of the safety equation.”

This article originally appeared in the October/November 2015 issue of COS.

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