Thanks to an inquiry from Australia yesterday from an earlier blog post, I thought I’d clarify the position in respect of the safest adhesive to use for hard hat and helmet labels. The history here is that in the 1979’s there were stories of motorcycle accidents where helmets were providing insufficient protection to the wearer’s head in a crash as the adhesive had significantly damaged the helmet surface and weakened it. You can read an interesting page on the subject here.
I tried to get a definitive answer to this question in 2007 from the EU technical manager for Fasson about the hard hat and helmet label adhesive we commonly specify for this application , and got this reply. “The history is that many years ago, during the 1970’s, polycarbonate crash helmets were introduced for motorcycle riders, and some time after this there we some issues with stickers coated with solvent based adhesives causing a weakening of the polycarbonate, reducing the effectiveness of the helmet. SInce this came to light we have stipulated the use of solvent-free, waterbased acrylic adhesives such as our S692N for this type of application. Although waterbased, S692N has excellent water resistance and good resistance to UV light making it ideal for outdoor exposure. “. Further consultation with an adhesive consultant suggested that any solvent based adhesive is a definite “no no”, normal hotmelts are undesirable, but any water based acrylic adhesive (used as standard on the vast majority of labelling material) is probably suitable, as are UV cured hotmelt adhesives (rare). If you want further advice, then please contact us.