Programmatic control of device I/O and EMF quiet mode, zone, signaling, and protocol are disclosed. Programmatic device I/O control reduces EMF radiation from a device with a device I/O controller application for programmatic control of the device's I/O channels. Responsive to firing of control rules, the device I/O application calls device APIs to control I/O channel settings. A quiet mode that reduces overall EMF radiation from a device is administered by an administrator and controls the device's wired or wireless I/O channels to create an EMF quiet zone in which some or all devices in a vicinity respond to a request to put themselves into an EMF quiet mode.