This collateral standard applies to electromagnetic compatibility of medical electrical equipment and medical electrical systems. The object of this collateral standard is to specify general requirements and tests for electromagnetic compatibility of medical electrical equipment and medical electrical systems. They are in addition to the requirements of the general standard and serve as the basis for particular standards. This edition of IEC 60601-1-2 was revised to structurally align it with the 2005 edition of IEC 60601-1 and to implement the decision of IEC subcommittee 62A that the clause numbering structure of collateral standards written to IEC 60601-1:2005 would adhere to the form specified in ISO/IEC Directives, Part 2:2004. The principle technical changes are in Clause 4, which now recognizes that there is a general requirement for a risk management process in IEC 60601-1:2005.