'non-inflammatory' is formed in modern English by adding the negative prefix 'non-' to the adjective 'inflammatory'. 'Inflammatory' ultimately comes from Latin 'inflammāre', where 'in-' meant 'in, on' (intensive) and 'flammāre' meant 'to set on fire'.

'inflammare' (Latin) passed into Old French as 'inflammer' and via Middle English forms such as 'inflamatory'/'inflammatory' became the modern English 'inflammatory'. The prefixed negative form 'non-' + 'inflammatory' is a more recent English formation to indicate the absence of that quality.

Initially related to 'setting on fire' (literal sense), the term evolved to mean 'causing physiological inflammation or provoking strong (often hostile) reaction'; with the prefix 'non-' it now expresses the absence of such inflammatory effect.