The color green was added to the photometric and color requirements for Class 3A and 3S devices to reflect the use of green warning lamps to identify an Incident Command Post, the private vehicles of volunteer firefighters or EMS personnel, or private security vehicles as described in U.S. Fire Administration document FA-336/February 2014, “Emergency Vehicle Safety Initiative.” Due to societal associations of the color green with the concept of normalcy (green GO signal of traffic lights, green indicator lamps to signify a device is operating within its normal operating limits, etc.), the color green shall not be used on its own for applications that require Class 1A, 1S, 2A, or 2S performance levels.
Electromagnetic interference guidelines were added for devices containing electronic controlling elements, converters, regulators, or actuators. Emergency, maintenance, and service vehicles utilize two-way radio communication devices that can be adversely affected by excessive electromagnetic emissions from warning devices.