Which method of accessing a scaffold is unsafe and should never be used?

Climbing on cross braces is considered an unsafe method of accessing a scaffold because cross braces are not designed to support the weight of a person. Cross braces are structural elements that provide stability and support to the scaffold system but are not intended for use as a means of access. Using cross braces for climbing can lead to loss of balance or the inability to safely navigate the scaffold, increasing the risk of falls or accidents.

In contrast, using a ladder, stepping on the planks (when they are properly placed and secured), and utilizing scaffolding wheels (in specific contexts, like when moving the scaffold) are generally safer practices. However, these options must still be executed correctly and within safety guidelines to ensure worker safety. Proper training and adherence to OSHA regulations are essential for accessing scaffolding systems safely.