A _We slid your question in front of Dave Thom, currently a Senior Consultant at Collision & Injury Dynamics in El Segundo, California, who has been testing protective headgear since 1981. Here's his take: "An excellent and timely question. Back in the day, there were only two helmet standards: DOT and Snell. More recently, manufacturers are offering helmets meeting one of two European standards-ECE and BSI-along with mandatory DOT compliance. Our laboratory testing and Dexter Ford's 2005 article explored the differences between these standards. All the helmets did very well and showed an industry-wide improvement from similar tests we performed in the early '90s. However, the Snell-qualified helmets had generally higher accelerations than those meeting the other standards.