Industrial safety helmets are impacted not only centrally from above, but also from the side by swinging loads such as those suspended from cranes. In addition, the wearer may be hit on the back of the head by a falling object whilst bending forward. In the past, it was not known whether the industrial safety helmet stipulated by EN 397 (Industrial safety helmets) for the construction industry offered sufficient protection against such impact and adequately absorbed it. The studies within the scope of the present project were to provide answers to these questions.
Side impact tests to EN 397 were performed on a number of industrial safety helmets. The Dummy Hybrid III was employed for this purpose. The dummy was fixed at the shoulders for this study, with the cervical spine and head free to move. The acceleration arising in the head in response to side impact from a swinging ball was measured at two different impact points. The head of the Dummy Hybrid III was first subjected to impact without helmet. Acceleration values of approximately 80 g were measured. The same test was then performed with 13 different industrial safety helmets. Of these 13 helmets, five were manufactured from thermoset materials, four from polyethylene (PE), and four from acrylonitrile butadiene styrene (ABS). The purpose of the study was to examine whether an industrial safety helmet also offers sufficient protection against impact from the side.
On all 13 industrial safety helmets, side impact resulted in measured acceleration values approximately 50 to 75% below the values arising in response to direct impact of the ball upon the head, i.e. of between 20 and 40 g. Values in this magnitude for acceleration of the head are considered at the present time to be insufficiently high to cause damage to the brain. No significant differences were observed between helmets of different geometry and material with regard to their absorption of side impact. The results of the study show that industrial safety helmets are capable of protecting the wearer's head effectively against injury caused by lighter impact from the side.
construction industryType of hazard:
Mechanische Gefährdung, Persönliche Schutzausrüstung, UnfallgefahrDescription, key words:
Industrial safety helmets, shock absorption, shock commutation, swinging loads, side impact, Dummy Hybrid III, acceleration measurement, cranial injury