Page 40 - OHS, June 2023

PPE: HEAD & FACE PROTECTION Photo courtesy of Mips Worker safety is at a critical juncture: Between 2003 and 2010, a total of 2,210 construction workers died of a traumatic brain injury. These deaths represented 25 percent of all construction fatalities. electrical insulation. Force transmission tests determine whether a helmet is able to reduce the force of a linear impact from a falling object to the crown of the wearer’s head. This serves as a clear reminder of the need to wear helmets on the job. The additional impact energy attenuation test, which is required for an ANSI Z89.1 type 2 helmet assignment, tests a larger protective area of the helmet with impacts on the side, front and rear of the helmet. However, it still only analyzes the linear accelerations and doesn’t test for the rotational motions that could be transmitted to the head. What is noticeably missing in the current standards’ regulations is testing for angled impacts to the head. Angled or off- center impacts are one of the most common accident scenarios and have a proven ability to cause brain injuries. However, today’s regulatory standards do not certify helmets based on their capability to assist in mitigating against rotational motion from an off-center or angled impact. It is encouraging to see that test standards in the moto and sports sectors are beginning to introduce the testing of angled impacts. This underscores the importance of both considering rotational motion and what a dangerous effect it can have on one’s head in the safety sector. r numerical computer simulations have demonstrated that the brain is more sensitive to rotational motion than linear motion in regard to concussions.7 Essentially, this means concussions caused by rotational motion occur at lower levels of energy than in cases involving linear motion. In other words, even impacts that may seem to be light can lead to concussions when rotation is a factor. Understanding How to Protect Yourself OSHA mandates that hard hats and head protection be worn by workers who are at risk for head injuries, but there are still many risks on construction sites that standard helmets don’t always account for. The first step is to wear a helmet and make sure that it fits both securely and comfortably on your head. Additionally, helmets equipped with rotational motion mitigation systems can be considered. Why the Construction Industry Must Care In the construction industry, the majority of TBIs that take place are not caused by an accident that occurs just as helmets are tested for, such as a pure linear impact to the crown of the safety helmet. Real life accidents, whether it be a falling object glancing the side of someone’s head or a fall, typically result in workers’ striking the safety helmet from an angle. On a job site, if someone were to slip and fall, they would most likely hit their head at an angle, which can lead to rotational motion. In order to keep workers safe, it is imperative that the potential causes of TBIs, including rotational motion, be addressed and receive greater awareness from those at risk. A survey from PPE provider J.J. Keller Safegear reported that the top reasons why employees did not wear their PPE were because they didn’t want to (72 percent) or they thought it wasn’t necessary (50 percent).8 Increased education around the risks of rotational i i n nj j u ur y y. . F 5 o 5, , 6 6 F u u r r t t h h e e r rm m o or r e e, , e e x x p pe er ri im me e n n t ts sa an nd d Th a n n k k t s t o m o m a a n n y y y y e e a s rotational motion, additional safety can be added to helmets to potentially help mitigate its impact. For instance, several rotational motion mitigation systems enable material in the helmet to slide and move relative to the wearer’s head. The intended outcome is to redirect rotational energy to linear energy, and consequently help reduce the amount of rotational energy that could otherwise be transferred to the brain. What To Know About Today’s Helmets Helmets have historically been designed to protect the wearer from linear forces. As is reflected in today’s regulatory standards, most helmets today work to protect wearers against a linear impact to the crown. For example, five performance tests must be met to assign safety helmets their classification according to the standard ANSI/ISEA Z89.1. These include impact energy attenuation, force transmission, flammability, apex penetration and Th a a r r s o s o f r f r e e s s e e a a r r c c h i h i n n t t o 38 Occupational Health & Safety | JUNE 2023 www.ohsonline.com