Review – Petzl Sirocco helmet

The big difference between the Sirocco and all other climbing helmets on the market is what it’s made from: expanded polypropylene. The advantage expanded polypropylene has over expanded polystyrene is that it is far more flexible and it won’t crack when bent, crushed or bashed. In fact, the expanded polypropylene is so tough you can basically smash the helmet against the rock – which I have done as a demo at the crag – without worrying about it cracking. Whereas an expanded-polystyrene helmet will generally crack when absorbing an impact, expanded polypropylene will absorb impacts with very little permanent deformation (see the video above if you doubt it), so it can take multiple impacts. It also means that it doesn’t require the plastic shell expanded-polystyrene helmets do to protect them against the rigours of a life in the vertical.