Antonyms of adj detrimental

1 sense of detrimental

Sense 1
damaging, detrimental, prejudicial, prejudicious -- ((sometimes followed by `to') causing harm or injury; "damaging to career and reputation"; "the reporter's coverage resulted in prejudicial publicity for the defendant")

INDIRECT (VIA harmful) -> harmless -- (not causing or capable of causing harm; "harmless bacteria"; "rendered the bomb harmless")

Similarity of adj detrimental

1 sense of detrimental

Sense 1
damaging, detrimental, prejudicial, prejudicious -- ((sometimes followed by `to') causing harm or injury; "damaging to career and reputation"; "the reporter's coverage resulted in prejudicial publicity for the defendant")
       => harmful (vs. harmless) -- (causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking")