noun
median lethal dose; LD50
Technical term used in toxicology and pharmacology; the dose of a substance that kills 50% of a test population.
この化学物質の半数致死量は非常に低い。
The median lethal dose of this chemical substance is very low.
半数致死量は毒性評価の重要な指標である。
The LD50 is an important index for toxicity assessment.
致死量 means 'lethal dose' in general, while 半数致死量 specifically refers to the dose that kills half of a test population.
Compound of 半数 (half the number), 致死 (lethal), and 量 (amount). The term is a direct translation of the English 'median lethal dose'.