As electronic cigarettes grow in popularity there’s an increasing amount of reporting about them in the news. A lot of this is quite alarming – every week or so a newspaper – usually the Daily Mail – declares that “new research” shows e-cigs are as dangerous as smoking. There’s some evidence that this has put many smokers off switching; they believe that if e-cigarettes are no safer than tobacco, there’s no point. Is this a reasonable attitude? What does the science actually say?
Many articles mention a review by the US FDA that found diethylene glycol in e-cig liquid. This is genuinely worrying because diethylene glycol, or DEG, is toxic to humans. What these articles don’t mention is that the study they’re quoting happened in 2008, and found DEG in one cartridge from a brand that’s no longer on sale. No trace of it has been found since, and even the contaminated cartridge had a DEG level that’s barely above the FDA’s safe limit.
Another common claim is that e-cigs contain antifreeze. In fact they don’t. This story seems to have appeared because e-liquid and modern antifreeze both contain propylene glycol. Of course so do most medications, most processed food and most asthma inhalers, but that’s not a problem – propylene glycol isn’t toxic.
The most recent claims have been that e-cig vapour contains formaldehyde, a chemical which can cause cancer (it’s also found in cigarette smoke). This is actually an interesting study. The researchers asked people to vape in a room, then sampled the air. Low levels of formaldehyde were detected, although they weren’t high enough to be of concern. However they also ran a control group – they sampled the air in a different room occupied by people who weren’t vaping. They found formaldehyde there, too. It turns out that low levels of it are produced naturally in the body and everyone exhales it!
Based on the evidence so far it seems that e-cigarettes do contain low levels of some toxic substances. However these levels are far below the amount needed to actually do any harm. Most people don’t realise that anything is toxic in large enough quantities; people die every year in the UK from water toxicity (but nobody has ever been poisoned by an e-cigarette!)