Antonyms of adj hazardous

1 sense of hazardous

Sense 1
hazardous, risky, wild -- (involving risk or danger; "skydiving is a hazardous sport"; "extremely risky going out in the tide and fog"; "a wild financial scheme")

INDIRECT (VIA dangerous) -> safe -- (free from danger or the risk of harm; "a safe trip"; "you will be safe here"; "a safe place"; "a safe bet")

Similarity of adj hazardous

1 sense of hazardous

Sense 1
hazardous, risky, wild -- (involving risk or danger; "skydiving is a hazardous sport"; "extremely risky going out in the tide and fog"; "a wild financial scheme")
       => dangerous (vs. safe), unsafe -- (involving or causing danger or risk; liable to hurt or harm; "a dangerous criminal"; "a dangerous bridge"; "unemployment reached dangerous proportions")