Which statement correctly describes signage for a boundary between a NERZ and an ERZ0?

• A. Signposted in intake airways and machine access leading into the boundary; facing into ERZ0.
• B. Signposted only at the boundary surface; facing toward the ERZ1.
• C. Signposted in all roadways; facing toward both zones.
• D. Not signposted.

Answer: (A)

The important idea is that warnings about entering a boundary between two zones must be provided where workers actually move toward that boundary, so they have a chance to take precautions before crossing.

Signage should be placed along intake airways and machine access that lead into the boundary, and it should face into the ERZ0 side. This makes the warning visible to anyone approaching the boundary from the NERZ side and entering ERZ0, giving timely notice to adjust procedures or PPE as needed. Placing signs only at the boundary surface delays awareness, signs in all roadways are unnecessary and cluttered, signaling toward both zones would be confusing, and not signposting at all would be unsafe.