safe vs unhazardous

safe is a noun but unhazardous is not a noun.

Word	Noun	Adjective	Verb	Adverb
safe	Yes	Yes	No	No
unhazardous	No	Yes	No	No

safe (noun)	unhazardous (noun)
strongbox where valuables can be safely kept
contraceptive device consisting of a sheath of thin rubber or latex that is worn over the penis during intercourse
a ventilated or refrigerated cupboard for securing provisions from pests

safe (adjective)	unhazardous (adjective)
free from danger or the risk of harm	thought to be devoid of risk
having reached a base without being put out
financially safe
(of an undertaking) secure from risk