Tree-Worker Safety Update

Be sure to wear the correct fall protection. Falls from aerial lifts most often involve overreaching and falling out of the bucket while not wearing (or connected to) fall protection. Fall-protection systems, like car-restraint systems, are an aerial-lift operator’s last line of defense in an incident and can make the difference between an injury and a fatality. Photo by Kathleen Costello.

Tree-worker safety has become a popular topic at tree care workshops and conferences. This is long overdue. If you look back to the 1950s, ’60s, ’70s, ’80s and even the ’90s, it was frequently an overlooked topic for programs. The National Arborist Association, now TCIA, addressed safety in Arbor Age magazine and later in TCI Magazine, but there was little coverage outside of these outlets.

TCIA has continued to lead in addressing this critical subject, and you can find numerous sessions on some aspect of safety at TCI EXPO and as article topics in TCI Magazine. The Accident Briefs listing in TCI is probably the most popular feature of the publication. The subject is addressed at ISA chapter conferences as well, where more speakers are covering safety topics.

However, there is a lot of discrepancy in the information being disseminated. This is not too surprising, as it really depends on how you define a tree worker. Is it someone who works for a tree company? Is it someone who is working for a landscape company but happens to be working on the tree when the incident occurred? Or is it anyone – paid or unpaid – who was working on a tree when they were hurt or killed?

Let’s refine it as tightly as we can and reduce the pool to include only individuals who were working for a tree company when the incident occurred. This eliminates the landscapers and land-clearing contractors who frequently are lumped together with tree workers in government statistics. It also eliminates the “weekend warriors” who own a chain saw and a ladder and, therefore, believe themselves to be qualified. These individuals account for the bulk of the emergency-department data on nonfatal injuries.

So, if we narrow the pool to fatal injuries involving only tree workers, what does it look like? First, the overall view looks worse. When you lump tree workers in with landscape workers and other contractors under landscape services, it pushes the overall fatality rate downward. The national all-industry, fatal-incident rate averages about four per 100,000 full-time equivalents. The landscape-services rate is 25 per 100,000, about six times higher than the all-industry average.

But landscape services include a lot of professions, some that are low risk. Garden planners and landscape architects, for example, do not have many incidents, and they lower the overall fatality rate. Landscape contractors have a higher fatality rate than the planners and designers; after all, they are operating heavy equipment and work near electrical conductors.

Even the workers performing commercial lawn care have a high fatality rate. Surprisingly, they often drown. This might seem like an unusual incident to many readers, but to anyone familiar with the retention ponds in the South, they understand these large commercial mowers can slide down slopes and overturn in the water.

The one group within the landscape-services category that has a still higher fatality rate is the tree worker. It’s difficult to separate all the workers out by specific categories for statistical reporting, but Michigan OSHA (MIOSHA) calculated a fatal injury rate for just tree workers of 45 per 100,000. Some states have calculated a higher rate. Regardless, this is a high-risk profession with a high fatal-incident rate. And it’s not getting better. The year 2016 had our highest number of recorded incidents in the past two decades – not a good incident trend.

So, what are these incidents, the ones specifically involving tree workers? Again, they vary based on what defines a tree worker, but taking the strictest definition, these are workers involved in tree pruning and removal and other tree care services (excluding pesticide applicators). Let’s look at the numbers nationally over the past decade.

First, they were almost exclusively male. About 99% of the fatalities occurred to men. They were also older men. Slightly more than half involved workers over the age of 45. Almost as many workers over 65 (4%) were killed as under 24 (6%)!

It takes a little less than five seconds for a mature tree to impact the ground once the back cut opens, and in that time the chain-saw operator can cover about 20 feet. Start moving the second the back cut starts to open and keep moving till the tree is on the ground. Photo by Richard May.

Older workers having the highest fatality rate is a common trend with most outdoor occupations. The older you are, the more likely you are to be killed. This does not mean younger workers, those under 45, do not have incidents. They have the most incidents, especially the young, new worker; it’s just that they survive them. The older you are, the more likely a serious injury will become fatal. It’s just a fact of life (or aging), like ear hairs, aches in the morning and needing to get up at 3 a.m. to pee.

The fatal injuries involved mostly multiple traumatic injuries, meaning more than one body part was affected (45%). One of the most common body parts was the torso or trunk, which sustained internal injuries to organs and blood vessels (20%). Multiple intracranial (within the skull) injuries also were common (15%), along with electrocutions (14%).

What were they doing when the fatal injury occurred? Let’s start by looking at what I call the “big-four” event categories: Falls, Contact with Objects and Equipment, Exposure to Harmful Substances or Environments and Transportation Incidents.


Falls, specifically falls to lower levels, have increased in proportion to the other events. Falls now account for about 44% of all the fatal incidents among tree workers. However, this is a recent trend. If you look back at the past two decades, Contact with Objects and Equipment had the highest percentage of incidents.

Most of the falls involved climbers who either disconnected from their climbing lines while repositioning or changing climbing systems or experienced failure of their anchors – the branch for their tie-in point. Movable rope systems (MRS), what we used to call double-rope technique or systems (DdRT), comprised most fall fatalities, but a significant number occurred with stationary rope systems (SRS), once called single-rope systems. A key hazard with SRS is failure to adequately test the top anchor and having the anchor isolated. If it fails, there is no backup. However, there have been incidents related to the selection of the basal anchor, including one where a truck driving between the tree and the basal anchor caught the line and dragged the climber out of the tree.

Falls from aerial lifts most often involve overreaching and falling out of the bucket while not wearing (or connected to) fall protection. I am no longer surprised at seeing the number of aerial-lift operators not wearing any fall protection. I have heard all the excuses: “It’s uncomfortable” or “It’s too expensive,” or my favorite, “I don’t plan on falling.” Fall-protection systems, like car-restraint systems, are an aerial-lift operator’s last line of defense in an incident and can make the difference between an injury and a fatality.

We also had falls from collapsing structures (trees) and equipment (aerial lifts). Tree workers still made fatal errors as they misjudged the structural integrity of the tree or the rigging forces.

Contact with Objects and Equipment

This is the event category with the second-highest number of fatal incidents, about 35% of the total. During much of the past decade, this category had the highest percentage of fatalities and still contains one of the leading activities for fatalities – manual tree felling. The fatal incidents from felling occurred primarily from two sources.

The first source is the chain-saw operator failing to follow a retreat path as the tree lifts. It is amazing how often a faller stands next to the trunk as it slowly, then with gathering speed, follows the arc to the ground. It’s fun (OK, I was guilty of this, too) to stand there and feel the wind come back at you. Fun, but not too smart. Almost all the chain-saw operators killed were within 10 feet of the stump, often as the trunk kicked back or rolled.

It takes a little less than five seconds for a mature tree to impact the ground once the back cut opens, and in that time the chain-saw operator can cover about 20 feet. Start moving the second the back-cut starts to open and keep moving till the tree is on the ground. Every foot reduces the chance of a fatal incident.

The second source involved ground workers, those holding lines and standing too close – less than 1.5 times the height of the tree. Realizing you’re standing in the shadow of the arc as the tree begins to fall is a little late to do much. The falling tree is moving at an average speed faster than you can jog, so outrunning it is not in your favor.

The other problem is ground workers who are not involved but still are standing too close. How often have you seen workers just standing there, waiting for the tree to fall? They need to be farther out than twice the tree’s height.

Exposure to Harmful Substances or Environments

The event category of Exposure to Harmful Substances or Environments includes environmental hazards such as heat and cold, but most incidents are due to exposure to electricity. Contact, either directly or indirectly, with an electric current comprised about 14% of tree-worker fatal incidents. About two-thirds of the contact incidents involved indirect contact, either through a detached branch or a pole saw.

Tree workers still have too casual an attitude when it comes to the hazards of electricity, and the amount of misinformation is incredible. I have heard that climbing lines cannot conduct electricity – wrong! Tree workers have died holding climbing lines that were touching wires. Or, that you can safely touch service wires – wrong again! We are not the only landscape-
services workers who are electrocuted. However, the threat to landscapers is more apt to involve standing on aluminum
ladders or operating rental lifts.

Transportation Incidents

If you compare these percentages to the TCI Magazine Accident Brief statistics, which include homeowners, or Bureau of Labor Statistics data for landscape services, you will find we are not as different as it seems in this category. We as tree workers tend to have proportionally fewer fatalities in Transportation, maybe because our trucks are bigger, though we have as many “struck-by passing traffic” incidents. The hazards of the roadside environment are shared by most members of the landscape-
services profession.

Violence and Other Injuries by Persons or Animals

A fifth category – not one of the big four, but worth mentioning – Violence and Other Injuries by Persons or Animals, includes insect stings. Someone in the tree care or landscape profession dies every year from an allergic reaction to a sting. Otherwise, most assaults are to gardeners and groundskeepers, not tree workers. Our assaults are either upset neighbors or co-workers; for example, a fairly recent incident involved a tree worker attempting to feed a co-worker into a chipper during an argument.

Finally, some other statistics on tree-worker fatalities:

• What is the month with the greatest number of fatal incidents? May (12%).

• The month with the least number? January (5%). The day of the week with the most incidents? Monday (20%), though not much more than Tuesday or Wednesday. The day with the least number? Sunday (5%). Friday is the workday with the lowest number of fatalities.

• How about time of day? Morning (55%), with most occurring midmorning (37%).

The most important point to all this is to never assume all these statistics apply to the “other workers.” I am willing to bet that every dead tree worker did not expect an incident to happen to them – it’s always the other worker who is careless. Remember, we are all the “other worker.”

Stay safe!

John Ball, Ph.D., BCMA, CTSP, A-NREMT (National Registry of Emergency Medical Technicians), is a professor of forestry at South Dakota State University in Brookings, South Dakota.

This article was based on his presentation on the same subject at TCI EXPO 2019 in Pittsburgh, Pennsylvania. Click below to hear that presentation.

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