The US, Canada, and Europe currently require compliance to edition 3.1 and officially adopted the 4th edition EMC requirements from December 31, 2018. Both new products and pre-existing products that are subject to a design change must comply with the 4th edition standard after the transition date. However, adoption of the various revisions of IEC 60601-1 around the world is a mixed picture, with transition to the 4th edition being unclear. This means products shipping internationally may require designs meeting more than one revision of the IEC standards or multiple versions of the same design in order to comply.