Electronic cigarettes (e-cigarettes), also known as vapes, are gaining popularity among youths in many parts of the world, including the US and Europe. [...] Passive vaping, or secondhand exposure, is a condition where bystanders, usually non-vapers, are exposed to the exhaled aerosol from e-cigarette use.

Unlike passive smoking, which includes the smoke released from the end of the burning cigarette (side stream), passive vaping only comes from the exhaled e-cigarette aerosol since the device does not yield side stream.