New research suggests that inhaling commonly used disinfectant chemicals could be significantly more harmful than ingesting them.

A study conducted by the University of California found that inhalation of quaternary ammonium compounds (QACs)—widely used in cleaning products—caused substantially greater lung damage in mice compared to oral exposure. These compounds, commonly present in surface disinfectants, fabric softeners, and certain personal care products, are not highly volatile but can become airborne when sprayed, increasing the likelihood of inhalation.

The study revealed striking results: inhaled QACs led to 100 times more lung injury and were 100 times more lethal in mice than the same chemicals consumed orally.

These findings raise concerns about the routine use of disinfectant sprays, particularly their potential link to respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD). Although the research was conducted on mice, scientists emphasize that the results point to a possible human health risk that deserves further investigation.

Lead researcher Gino Cortopassi highlighted the implications, stating that the findings call into question the widespread presence of QAC-based disinfectant sprays in everyday environments, given their demonstrated lung toxicity in animal models.

Earlier research by the same team also found that QACs are already prevalent in humans. A 2021 study showed that approximately 80% of participants had detectable levels of these chemicals in their blood. Higher concentrations were associated with reduced mitochondrial activity in immune cells, indicating a potential impact on the body’s energy production and immune function.