Glass installed on logging machines must:

(1) Be free of deposits of oil and mud or defects that could endanger the operator or other employees;

(2) Be safety glass or a type that provides equal protection;

(3) Be removed or replaced if defective or broken glass impairs the vision of the operator; and

(4) Have an additional metal screen or guard installed where glass does not provide adequate operator protection from flying chokers, chunks, saplings, limbs, etc. The operator's vision must not be impaired.