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The standardized test method in accordance with DIN 4840, such as it applies at present, does not
provide any reliable information on the protective properties of aged safety helmets. The specification
requiring helmets to be resistant to penetration should be completed by another safety requirement
stipulating that the penetration of the test cone must not generate any material-seperating cracks other
than those occuring at the point of contact. In addition, the manufacturer has to ensure satisfactory
UV-stability of the material.
Artificial aging, solely by exposure to UV-radiation, appears to be a suitable method which enables a
comparative analysis of safety helmets to be carried out under less time-consuming and better
reproducible conditions than there are in open-air weathering.
In the case of thermoplastic helmets, material embrittlement can be determined by means of the so-called
?crackling test? and, sometimes, on the basis of alterations in the colour. For the user, these are possible
ways to get at least an idea of the protective properties a helmet still offers.
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