The spirit moves them to take safety first (5)
I believe the answer is:
meths
'the spirit' is the definition.
(I've seen this before)
'moves them to take safety first' is the wordplay.
'moves' indicates an anagram.
'to take' says to put letters next to each other.
'safety first' becomes 's' (1st letter of 'safety').
'them' is an anagram of 'meth'.
'meth'+'s'='METHS'
(Other definitions for meths that I've seen before include "Violet-coloured alcohol" , "Fuel" , "unsuitable alcohol" , "Spirit" , "Methylated spirits (colloq.)" .)