Final answer:
Medium length hair should generally be secured in lab settings or workplaces where safety is a concern. This is to prevent accidents and contamination, along with wearing safe attire like closed toe shoes.
Step-by-step explanation:
Whether medium length hair must be secured can depend on the context, such as in a lab setting or certain workplaces.
Generally, if you're in a setting that requires safety precautions like a chemistry laboratory or a culinary class, it's recommended to tie back long hair to prevent any accidents or incidents where hair could become a hazard or contaminate the work area.
Likewise, proper attire such as wear closed toe shoes with flat heels and shirts without loose or dangling elements is also advised for safety reasons. Thus, securing medium length hair can be part of broader safety guidelines to minimize risks.