Can disinfectant sprays with quaternary ammonium compounds damage your lungs?

What's actually in it

Most disinfectant sprays, wipes, and surface cleaners contain quaternary ammonium compounds (QACs), also called "quats." Brands like Lysol, Clorox, and countless store-brand cleaners rely on these chemicals to kill bacteria and viruses. When you spray them, tiny droplets hang in the air and you breathe them in. QACs are also in some hand sanitizers, laundry detergents, and fabric softeners.

What the research says

A 2026 study in Environ Sci Technol tested what happens when QACs are inhaled. The researchers exposed lab animals to aerosolized quaternary ammonium compounds at concentrations similar to what you'd breathe during a normal cleaning session.

The results showed clear lung tissue damage. The chemicals triggered inflammation in the airways, damaged the cells lining the lungs, and disrupted the immune response in lung tissue. The damage was dose-dependent: more spray meant more harm.

One surprising finding was that the effects were sex-specific. Female subjects showed worse lung damage than males at the same exposure level. The researchers believe this may relate to hormonal differences in how the lungs repair themselves.

The study tested several common QACs and found toxic effects across the board. There wasn't one "safe" version. The chemicals that make your countertop germ-free are the same ones irritating your airways every time you spray.

Using a cloth dampened with cleaner instead of spraying reduces airborne exposure. Good ventilation, like opening a window while cleaning, also cuts down on what you inhale.