Originally Posted by Prendas in the UK

Important information for Customers Outside the European Union: The Whisper Helmet is designed for use in the European pro peleton and therefore meets the EN1078 European safety standard. If your country requires a different and/or more stringent standard neither Prendas Ciclismo nor Catlike can take any responsibility for the use of the Whisper in these circumstances.
Additional information for USA Customers: Whilst the Whisper does not meet the CPSC standard, as of the 3rd March 2006, USA Cycling added the European helmet standard to its list of approved standards.