Using bleach together with bathroom cleaners to remove stubborn stains can be a fatal habit that has caused deaths, a chemistry expert has warned.
Choi Eun-jung, a doctor of science education at Ewha Womans University, appeared on the YouTube channel "Doctor Friend" on the 8th and said, "The problem with bleach is that it generates chlorine gas. Mixing it with bathroom cleaners or detergents is a dangerous practice."
When bleach is combined with acidic cleaners such as vinegar or citric acid, or with kitchen and bathroom detergents, toxic chlorine gas is produced. Choi said the gas is the same substance used as a lethal weapon during World War I, adding that a housewife in Japan died after mixing a cleaner with bleach while cleaning.
Wearing a mask offers no protection. "Chlorine gas passes through masks," Choi said. "The particles are so small that even a KF-94 mask cannot filter them out."
Choi also pointed to the strong alkaline nature of bleach as a risk factor. "During preparation for a broadcast experiment in the past, I was exposed to bleach for an extended period and was diagnosed with chemical pneumonia," she said. "The gas seeps between the alveoli in the lungs and does not escape easily. There is no proper medication for it, and I suffered for more than a week."
She added that "hair dissolves in just 15 minutes when soaked in bleach," illustrating bleach's powerful protein-breaking capability. She noted that "mild mold removers" sold commercially are also largely composed of sodium hypochlorite, making them essentially the same as bleach.
Regarding cleaning products marketed with claims such as "safe because it's made from salt," Choi stressed, "Sodium hypochlorite is a completely different substance from salt. You should not assume it is safe just because it contains sodium." She said "soda" products such as baking soda and sodium percarbonate also have entirely different properties despite their similar names, and that sodium percarbonate has a far stronger alkaline nature than ordinary baking soda.
Choi suggested ways to clean bathrooms without using bleach. She explained that dissolving sodium percarbonate in warm water at around 50 to 60 degrees Celsius, or mixing in a small amount of toothpaste if needed, creates an abrasive effect that helps remove stubborn stains.
She advised that dish towels can be sufficiently disinfected by wetting them and microwaving them for 30 seconds to one minute. For removing limescale from shower heads, she said using a citric acid solution is safer than bleach. Baking soda is more useful for regular maintenance rather than removing deep-set stains, she added.
"I do not recommend using bleach at home," Choi repeatedly emphasized. She explained that while bleach may be used in institutional settings such as school cafeterias for infection control purposes, ordinary households can clean sufficiently without it.