Which of the following represents an alternative effective protection in a workplace?

Interlocked gates and barriers are an effective alternative protection method in the workplace, particularly in environments where machinery poses hazards to employees. These mechanisms function by preventing access to dangerous areas or equipment while the machinery is in operation. When interlocked gates are in place, they ensure that equipment cannot be activated or continued in operation if the gate is open, thus significantly reducing the risk of accidental injuries.

Such systems provide a physical barrier that, when combined with other safety measures, enhances overall workplace safety and ensures compliance with regulations. They are particularly useful for controlling access to hazardous areas and helping to enforce lockout/tagout procedures by ensuring that workers cannot access equipment that is meant to be shut down for maintenance or repair.

In contrast, the other options, while beneficial in a safety program, do not serve as direct physical barriers to machinery operation. Regular manual inspections help identify hazards but do not prevent access. Frequent operator training sessions improve awareness and knowledge of safety procedures but do not physically protect workers, and personal protective equipment (PPE) can mitigate injuries but does not prevent the source of danger itself.