U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
(a) Warning signs must be conspicuously placed along each protective enclosure at intervals so that at least one sign is recognizable at night from a distance of 30m (100 ft.) from any way that could reasonably be used to approach the enclosure.
(b) Signs must be marked with at least the following on a background of sharply contrasting color: