ISO 13850:2006 specifies functional requirements and design principles for the emergency stop function on machinery, independent of the type of energy used to control the function. It is applicable to all machinery except for machines in which the provision of emergency stop would not lessen the risk, and hand-held portable machines and hand-guided machines. It does not deal with functions such as reversal or limitation of motion, deflection, shielding, braking or disconnecting, which can be part of the emergency stop function.