WordNet sense 1 (not producing or resulting from poison):

nontoxic, atoxic

WordNet sense 2 (free from danger or the risk of harm):

safe

WordNet sense 3 (not offensive):

inoffensive

WordNet sense 4 (having no adverse effect):

innoxious

WordNet sense 5 (causing no harm):

unoffending

WordNet sense 6 (lacking intent or capacity to injure):

innocent, innocuous

WordNet sense 7 (not threatening to life or health; not malignant):

nonmalignant

WordNet sense 8 (pleasant and beneficial in nature or influence):

benignant