Transport units carrying dangerous goods shall have two vertically positioned rectangular orange-coloured plates. They shall be placed so that one is at the front and the other at the rear of the transport unit, both perpendicular to its longitudinal direction. They shall be clearly visible. If a trailer containing dangerous goods is uncoupled from its motor vehicle during transport, the trailer shall still be fitted with an orange-coloured plate at the rear.

The orange signs must not come loose from their attachment in a 15-minute fire. They must remain attached regardless of the vehicle's position or orientation.

If the size and construction of the vehicle are such that the available surface is insufficient to affix the orange-coloured plates, their dimensions may be reduced to 30 cm width, 12 cm height and 10 mm wide black frame.

For complete instructions on how orange-colored plates should be applied to different types of transport units, please refer to the ADR regulations and chapter 5.3.2 Marking with orange-colored plates.