Under what condition must the manufacturer verify that ESD controls are adequate?

The correct choice highlights a crucial aspect of managing electrostatic discharge (ESD) risks. When humidity falls below 30%, it significantly increases the potential for static electricity build-up, as dry air is a conducive environment for electrostatic charges to accumulate. In such low-humidity conditions, the likelihood of ESD events that can damage sensitive electronic components rises. Therefore, manufacturers must verify that ESD controls are adequate to protect against potential damage in these situations.

Understanding this context is vital for ensuring that appropriate safety measures, such as grounding, use of ESD-safe materials, and proper handling procedures, are in place. This response helps emphasize why monitoring humidity levels is essential in environments where sensitive components are handled and assembled.