Some e-cigarettes emit more harmful chemicals than others, study finds
Type and temperature of the vapouriser can affect how toxic its emissions are
Two more carcinogens have been identified in e-cigarettes liquid.
Concerns have been raised in the past about the possibly toxic emissions that electronic cigarettes produce, from formaldehyde to diacetyl - a chemical connected to lung disease.
But a new study has discovered the presence of propylene oxide and glycidol, two probable carcinogens.
These study by the Lawrence Berkeley Laboratory in California, published in Environmental Science and Technology, shows that the type and temperature of the vapouriser can affect how toxic its emissions are.
As part of their research, the team used two different e-cigarettes and stimulated vaping at different battery settings.
When they tested emissions from an e-cigarette that housed two heating elements, these had a lower concentration of harmful chemicals than the single-coil model.
That's because the same voltage gets distributed evenly with two coils so they can each be heated at a lower temperature, therefore reducing the levels of harmful emissions that are produced.
Researchers hope that the discovery of the link between temperature and toxins could lead to better regulations and products.
The study also found that the age of the e-cigarette could make it more harmful; the longer the e-cigarette had been used, the higher the levels of chemicals is released.
Study co-author Hugo Destaillats said: Regular cigarettes are super unhealthy. E-cigarettes are just unhealthy."