Regularly tamper with gown and PPE (5)
I believe the answer is:
apron
'ppe' is the definition.
(type of personal protective equipment)
'regularly tamper with gown' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'with' is a charade indicator (letters next to each other).
'gown' becomes 'on' (I can't justify this - if you can you should believe this answer much more).
The alternating letters of 'tamper' are 'apr'.
'apr'+'on'='APRON'
'and' is the link.
(Other definitions for apron that I've seen before include "Area for aircraft not in use" , "Garment for protection" , "Cook's garment" , "Area around aircraft hangar" , "Protective garment - part of stage" .)