The problem with the adaptors sold for use in Australia, New Zealand, continental Europe, Argentina, Brazil and South Korea is that "in very rare cases" some of them may break, leading to a risk of electric shock.
Apple says it is aware of 12 such incidents.
Adaptors sold as part of the World Travel Adapter Kit may also be affected.
The company's other wall plug adaptors, including those for United States, United Kingdom, China and Japan, and the Apple USB power adaptors are not covered by the exchange program
Apple will exchange the affected adaptors at Apple Stores (but it'll be best to reserve a spot at the Genius Bar before you go) or Authorised Apple Service Providers. Customers can also contact Apple support.
The replacement will be provided free of charge, but customers will need to quote the serial number of the Mac, iPad, iPhone or iPod that the adaptor was supplied with.