How to say "toxic" in Japanese

• 有毒ゆうどくCommon
  na-adjective, no-adjectiveCovers the basic sense of 'toxic': describing a substance that is poisonous or contains poison, such as harmful fumes, plants, or chemicals. This is the word you want when you mean that something is toxic.
  この食品しょくひんは有毒ゆうどくである。↗

  This food is unhealthy.
• 毒性どくせいCommon
  no-adjectiveReally the noun 'toxicity': the poisonous property or strength of a substance, also virulence. Use it for 'toxic' when the focus is on that property or degree rather than on calling something poisonous.

Use 有毒 for the plain sense of 'toxic' — a substance that is poisonous or contains poison; 毒性 is really the noun 'toxicity', the strength or degree of a substance's poison, fitting 'toxic' when that property is the focus.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 有毒ゆうどくpoisonous
• 毒のあるどくのあるpoisonous
• 中毒性ちゅうどくせいpoisonous
• 毒性どくせいtoxic