Definition of non-irritant in US English:
non-irritant
adjective
Pharmacology
Of a substance: not causing irritation of the skin or other tissue.
noun
Pharmacology
A non-irritant substance.
Origin
Mid 19th century; earliest use found in Proceedings of the Royal Society of London. From non- + irritant.
Pronunciation
non-irritant
/nɒnˈɪrɪt(ə)nt/