T  h  i  n  k    hard,  work
Long hair and jewelry comprise a hidden hazard.   Chains, watches, and other jewelry can easily get caught in the moving parts of equipment, as can long hair.   Not only could this damage the equipment, but it could maim us or even cost us our lives in some cases.
Better to be safe than sorry.   Cut the hair, and don't wear jewelry or loose-fitting clothing around any machinery which could pose a danger in this regard.
The responsibility for the safe operation of machinery falls to the operator.   In other words, spend adequate time on preparation to prevent compromising situations.   Read and follow user's manuals and all other general safety guidelines.