In a post published earlier today, I argued that the Kentucky Center for Smoke-Free Policy was lying in telling the public that "formaldehyde (embalming fluid) is just one of the toxic chemicals in the liquid and the aerosol."
It turns out that formaldehyde has been detected in a number of e-liquids. At the time, I was not aware of the fact that formaldehyde was present in many e-liquids. I was only aware that it was a by-product of overheating of propylene glycol and that it therefore appeared in the aerosol of some brands of e-cigarettes.
I therefore stand corrected. In the Varlet et al. study published earlier this year, formaldehyde was present in the e-liquids tested at a concentration ranging from 0.06 ug/g to 9.00 ug/g.
While it is still untrue to claim that embalming fluid is a toxic chemical present in e-liquids (since embalming fluid itself is not added to e-liquid), it is true that formaldehyde is present in many e-liquids as well as in e-cigarette aerosol of some products.
Therefore, I apologize to the Kentucky Center for Smoke-Free Policy and retract my claim that they are lying to the public in telling us that there is formaldehyde present in e-liquids.
The Rest of the Story
The presence of formaldehyde in many e-liquids is troubling for several reasons.
First, it suggests that the presence of formaldehyde in many e-cigarette brands is not exclusively due to the formation of formaldehyde upon overheating of the e-liquid. It is possible that in some cases the formaldehyde is a contaminant already present in the e-liquid and that it enters the aerosol directly from the liquid without requiring overheating and a degradation process.
Second, this suggests that the standards used in e-liquid production are not nearly as good as I thought they were. The presence of formaldehyde in the e-liquids suggests that low quality raw materials are being used in the production process. It is also possible that formaldehyde is present in some of the flavorings used
Third, this has implications for e-cigarette regulation because it suggests that the regulation of coil temperature may not be sufficient to protect against the presence of formaldehyde in the aerosol. Instead, it may be that the FDA needs to simply set standards for the maximum allowable concentration of formaldehyde in the e-vapor (i.e., aerosol) and require each company to test and confirm that the aldehydes in the aerosol of their products do not exceed specified levels (acetaldehyde is also of concern).
The rest of the story is that given this new information, I believe that setting specific quality standards for electronic cigarettes is now an absolute necessity. The FDA must abandon its preliminarily indicated approach of requiring tens of thousands of pre-market applications that will take years to process and instead must simply promulgate minimum quality standards that all companies must follow. Anything short of this will fail to protect the public's health and will potentially put vapers at unnecessary excess risk for a matter of years. The quality standards must include maximum allowable levels of e-liquid and aerosol contaminants, especially diethylene glycol, ethylene glycol, formaldehyde, acetaldehyde, and acrolein.