(a)
no employee operates a powder actuated tool unless the employee
(i)
has been trained in the use of the specific make and model of the tool to be used and is in possession of a valid operator’s certificate,
(ii)
is competent to use the tool, and
(iii)
is authorized to use the tool, and
(b)
all powder actuated tools and their explosive charges are kept in a storage area that is accessible only to persons who are authorized to handle them.