Children and Infants
RISK: ELEVATED Children breathe faster than adults (absorbing more particles per body weight), their lungs are still developing, and nicotine exposure during childhood can affect brain development. The American Academy of Pediatrics recommends a zero-exposure policy for children. Secondhand vape exposure in children has been linked to increased respiratory infection risk in preliminary studies, though evidence is still emerging.
Pregnant Women
RISK: ELEVATED Nicotine crosses the placenta and is present in breast milk. While the risk from secondhand vape is far lower than from secondhand smoke, the CDC recommends that pregnant women avoid all nicotine exposure, including secondhand. The evidence for harm specifically from secondhand vape (vs direct vaping or smoking) is limited, but the precautionary principle applies. See our mental health and vaping research for nicotine's neurological effects.
People with Respiratory Conditions
RISK: ELEVATED Asthma and COPD patients may experience airway irritation from secondhand aerosol. The 2025 European Respiratory Journal review found that asthmatic subjects exposed to secondhand vape for 1 hour had a small but measurable decrease in FEV1. Propylene glycol, the primary base liquid, can act as a respiratory irritant in sensitive individuals. For the full respiratory evidence review, see our lung health guide.
People with Cardiovascular Disease
RISK: THEORETICAL No studies have shown acute cardiovascular effects from secondhand vape in people with heart disease. However, given that nicotine can cause vasoconstriction and elevated heart rate (effects documented in our VapeScan study review), cardiac patients should minimize exposure as a precautionary measure.
