sodium hypochlorite is generally sold in aqueous solutions containing 5 to 15% sodium hypochlorite, with 0.25 to 0.35% free alkali (usually NaOH) and 0.5 to 1.5% NaCl. Solutions of up to 40% sodium hypochlorite are available, but solid sodium hypochlorite is not commercially used. Sodium hypochlorite solutions are a clear, greenish yellow liquid with an odor of chlorine. Odor may not provide an adequate warning of hazardous concentrations.

sodium hypochlorite solutions can liberate dangerous amounts of chlorine or chloramine if mixed with acids or ammonia. Anhydrous sodium hypochlorite is very explosive. Hypochlorite solutions should be stored at a temperature not exceeding 20ºC away from acids in well-fitted air-tight bottles away from sunlight.