Quick Facts

• Regular use of spray cleaners causes lung function decline equivalent to smoking a pack of cigarettes daily
• Breathing quaternary ammonium compounds causes 100 times more lung injury than swallowing them
• Women using chemical disinfectants once weekly have 32% higher risk of developing COPD

Common household cleaners pose a far greater threat to respiratory health than previously understood. A 2026 University of California, Davis study published in Environmental Science and Technology found that breathing disinfectant chemicals called quaternary ammonium compounds causes 100 times more lung injury than swallowing them.

“The surprising result of this study was that these compounds, when inhaled, caused 100-fold more lung injury and 100-fold more lethality compared to oral ingestion,” said Dr. Gino Cortopassi, the study’s lead researcher.

A landmark European study following over 6,000 participants found women who regularly used spray cleaners experienced lung function decline roughly equivalent to smoking a pack of cigarettes every day. The research showed accelerated decline in lung capacity among both home cleaners and occupational cleaning workers.

The health risks extend beyond immediate exposure. A Harvard study of more than 55,000 US nurses spanning thirty years found those who used chemical disinfectants just once per week had a 32% higher risk of developing chronic obstructive pulmonary disease (COPD).

Quaternary ammonium compounds, the primary chemicals of concern, are found in most commercial disinfectants. Their use expanded dramatically during the COVID-19 pandemic. Research shows QAC levels in household dust roughly doubled compared to pre-COVID levels.

“Breathing in QACs can cause irritation of the nose and throat. Some QACs can trigger asthma symptoms if you already have asthma or can even cause asthma in people who have never had it before,” according to recent research published in Expert Review of Respiratory Medicine.

Women face disproportionate exposure because they handle most household cleaning tasks and represent the majority of professional cleaning workers. Children are particularly vulnerable due to higher breathing rates and tendency to breathe closer to the ground where pollutants concentrate.

Healthcare workers, janitorial staff and institutional cleaners represent the most heavily exposed populations. Recent studies document an epidemic of asthma-like symptoms among professional cleaners.

Current regulations fail to protect consumers. US law does not require manufacturers to list all ingredients in cleaning products. This makes it impossible to know exactly what chemicals you’re breathing and their long-term health effects.

Experts recommend avoiding spray cleaners entirely. If you must use them, spray into a cloth rather than directly on surfaces to reduce inhalation of droplets. Safer alternatives include ethanol, hydrogen peroxide, or citric acid-based cleaners, which are EPA-registered to kill bacteria and viruses including SARS-CoV-2.

“You could use air purifiers or a mask, but ideally you just wouldn’t use those substances,” advised Mary Margaret Johnson, principal research scientist at Harvard T.H. Chan School of Public Health.

Read more: These Common Cleaners Could Be Doing Serious Damage To Your Lungs