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Steve Rowson is a professor of biomedical and mechanical engineering and director of the Helmet Lab at Virginia Tech. The opinions are the author’s own.
In the United States, construction is responsible one in five occupational deaths and almost half of all falls, slips and deadly troops. Almost 60% of deaths from traumatic brain injuries in this industry they come from falls. Many of these deaths could have been prevented with better head protection that stays on the head during a fall and dissipates the energy of the impact.
At the Virginia Tech Helmet Lab, we’ve spent years studying how helmets handle impact energy. In sports, this work helped drive major improvements in design. When we applied the same methods to building helmets, we found a clear opportunity for progress.
The industry has relied for decades on Type I helmets, designed to protect against a tape measure or wrench dropped from above. They use a suspension system to absorb vertical impacts, but do not have a chin strap and are not padded. Type II helmets add chin straps and internal padding that can diffuse energy during impacts.
Our tests showed that the difference is not subtle. Compared to Type I helmets, Type II helmets reduced the risk of fall-related concussion by 34% and the risk of skull fracture by 65% on average. For the higher performance helmets, these reductions reached 48% and 77%. These numbers mean that many fall-related head injuries and deaths are preventable right now.
Selection of hats
So why are Type I helmets still the norm in most workplaces? Workers often describe Type II helmets as hotter or heavier, and companies cite cost. Another factor is the lenient standard of proof. Under the ANSI/ISEA Z89.1 specification, the US safety standard for industrial head protection, there is little incentive for manufacturers to exceed minimum performance requirements.
Steve Rowson
Permission granted by Peter Means/Virginia Tech
Type I helmets are only tested for force penetration and transmission, not impact energy absorption. Type II helmet certification includes an energy attenuation test, but the condition represents a drop of about two feet, a far cry from a worker falling from a height. As a result, even helmets that meet the current standard are certified under far less severe impacts than those that kill workers.
To understand what happens in real falls, we recreated them. Focusing on severe but survivable drops from heights of 14 to 25 feet, we tested the helmets at impact energies three times higher than those rated by the standard. Type II helmets absorb substantially more energy and their chin straps will keep the helmet in place during a fall. Type I helmets are unlikely to remain on the head during a severe fall.
A helmet can only do its job if it stays between the head and the impact surface.
These findings show that the technology already exists to protect workers from the most serious head injuries. The problem is adoption. Data should drive safety decisions, and Helmet Lab’s recently released STAR ratings for construction helmets provide that data. STAR, short for Summation of Tests for the Analysis of Risk, identifies which standard-certified helmets offer the most effective energy management under real-world conditions. This should be the starting point for the industry.
As manufacturers integrate higher-energy testing into their R&D processes and contractors choose equipment accordingly, the next generation of helmets will prevent injuries that are still considered unavoidable today.
Simply put, construction workers should wear Type II hard hats whenever there is a risk of a fall or impact to the head. Making this change will help prevent debilitating injuries and save lives.
