noun
bleaching powder; chlorinated lime
A white powder used as a bleaching agent and disinfectant; chemically, calcium hypochlorite.
プールの消毒に晒し粉を使う。
Bleaching powder is used to disinfect swimming pools.
漂白剤 is a general term for bleaching agents, while 晒し粉 specifically refers to bleaching powder (calcium hypochlorite).
Compound of 晒し (さらし, 'bleaching', from verb 晒す) and 粉 (こ, 'powder').