Which statement regarding facial hair restrictions is false?

The statement regarding handlebar mustaches being allowed is false because the policy on facial hair typically aims to ensure that facial hair does not interfere with the proper fit and seal of personal protective equipment, especially respirators. Handlebar mustaches, which are styled with the ends curled up, can pose a challenge in creating a secure seal necessary for safety during firefighting operations.

In contrast, the other statements reflect common grooming standards where mustaches are required to be kept to specific lengths and in particular styles to comply with safety protocols. The trimming of mustaches to expose the lip and the restriction on how far they can extend below the mouth both align with the importance of maintaining a safe and professional appearance while ensuring equipment effectiveness. Lower lip whiskers being permissible is often part of personal grooming policies that allow for some expression while still adhering to necessary safety precautions.