Is Second-Hand Vape Harmful? Understanding the Risks and Facts

Second-hand vaping occurs when a non-vaper passively inhales the vapor exhaled by someone using an e-cigarette.

Unlike traditional cigarettes, which release smoke from both the burning tobacco and the smoker’s exhalation, e-cigarettes only produce aerosol when the user exhales.

Key differences between second-hand vaping and second-hand smoking include:

• Lack of combustion: Vaping does not involve burning tobacco, meaning there is no tar or carbon monoxide.
• Lower levels of harmful chemicals: Studies show that e-cigarette aerosol contains fewer toxicants than cigarette smoke.
• No sidestream emissions: Cigarettes continuously emit smoke from the lit end, whereas e-cigarettes only release vapor when exhaled.

While this suggests that second-hand vapor exposure may be less harmful than second-hand smoke, researchers are still investigating its long-term effects.

E-cigarette aerosol contains:

• Nicotine (if present in the e-liquid) – A stimulant that can affect the nervous system.
• Propylene Glycol & Vegetable Glycerin – Common food additives used as the base for e-liquids.
• Flavoring Chemicals – Some flavors contain compounds like diacetyl, which has been linked to lung conditions.
• Trace Metals – Studies have detected small amounts of metals such as nickel, tin, and lead.
• Volatile Organic Compounds (VOCs) – Some VOCs, like benzene, have been classified as harmful.

However, the concentration of these substances in exhaled vapor is significantly lower than in cigarette smoke.

According to a 2016 study by the University of California, San Francisco, 94% of the nicotine inhaled during vaping stays in the user’s body, with only 6% being released into the air.

The potential risks of second-hand vaping depend on several factors, including exposure levels, the presence of nicotine, and the environment where vaping occurs.

Current Research Findings

• A study published in Thorax found that second-hand vapor exposure is associated with increased risk of bronchitis symptoms and shortness of breath, particularly in young adults.
• Research from the University College London (UCL) concluded that nicotine absorption from second-hand vaping is significantly lower than from second-hand smoking—about 84% less.
• A 2021 study in Tobacco Control found that vaping indoors increases fine particulate matter, which can affect respiratory health over time.

Despite these findings, experts caution that more long-term research is needed to determine the full health impact of second-hand vaping.

Second-Hand Vaping vs. Second-Hand Smoking

• Second-hand smoke contains over 7,000 chemicals, including carbon monoxide, arsenic, and formaldehyde.
• Second-hand vapor contains fewer toxicants, and studies suggest that most nicotine is absorbed by the vaper before being exhaled.
• The UCL study found that children exposed to indoor vaping absorb far less nicotine than those exposed to indoor smoking.

While second-hand vaping appears to be much less harmful than second-hand smoking, complete safety is not yet confirmed.

Babies and young children are more vulnerable to environmental pollutants due to their developing lungs and immune systems.

Potential Concerns

• Nicotine Exposure – Even small amounts of nicotine can affect brain development in young children.
• Allergic Reactions – Some e-liquids contain ingredients that may trigger allergies.
• Surface Contamination – Residual chemicals from vapor can settle on surfaces, which children may touch or ingest.

Although studies show that second-hand vaping exposure is much lower than second-hand smoke exposure, experts recommend not vaping around babies or children as a precautionary measure.

If you vape, consider these steps to minimize second-hand vapor exposure:

• Vape in well-ventilated areas to disperse vapor quickly.
• Avoid vaping around non-vapers, children, and pregnant women.
• Choose nicotine-free e-liquids if vaping around others.
• Use high-quality e-liquids to avoid exposure to harmful additives.
• Follow regulations and respect others’ preferences regarding vaping in public spaces.

While second-hand vaping is considered lower risk than second-hand smoke, taking precautions can further reduce any potential risks.

Despite being unharmful to people around, it is essential to respect the concerns of people around vapers, including friends, families, and colleagues, about second-hand vaping vapor. That is why you should only vape in designated areas. However, suppose you ever have to use your e-cigarettes in public places or among other people. In that case, you should ask if they are comfortable inhaling the second-hand vapor from your e-cigarettes. Finally, it would be best to not vape around your baby.