Administrator from former chemicals company always has no manners (8)
I believe the answer is:
official
'administrator' is the definition.
(I know that administrator can be written as official)
'from former chemicals company always has no manners' is the wordplay.
'from' becomes 'off' (eg someone might be from or 'off' a TV show).
'former chemicals company' becomes 'ICI' (Imperial Chemical Industries, former company).
'has no' is a deletion indicator.
'manners' becomes 'ways' (I've seen this before).
'always' with 'ways' taken away is 'al'.
'off'+'ici'+'al'='OFFICIAL'
(Other definitions for official that I've seen before include "Publicly maintained" , "Public employee" , "Authorative" , "agent" , "Bureaucrat" .)