The European Standard - EN50291
This standard will supersede the British Standard BS7860 in April 2006

This standard was implemented in April 2001. Products officially approved to this standard must be clearly marked with the EN50291 number and may also display the Kitemark symbol. This standard is running in parallel to the British Standard up until April 2006. This is to allow all manufacturers of BS approved products to change over to the new European standard.

After April 2006 the only valid standard across Europe will be EN50291.

Main alarm requirements:
at 30ppm CO, the alarm must not activate for at least 120 minutes
at 50ppm CO, the alarm must not activate before 60 minutes but must activate before 90 minutes
at 100ppm CO, the alarm must not activate before 10 minutes but must activate before 40 minutes
at 300ppm CO, the alarm must activate within 3 minutes