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How to Ensure the Safety of E-Cigarettes

by Shalini Chandrasekaran

What are e-cigarettes?

E-cigarettes or “e-cigs” are battery operated machines which unlike conventional cigarettes, convert nicotine into vapor instead of smoke, and are often rechargeable. Their cartridges, containing an “e-liquid” mainly comprised of nicotine and other chemicals in smaller quantities, can be replaced by the user. For the discreet consumer, some e-cigs come disguised as a pen or even a USB stick. Moreover, e-cigarettes appeal to the younger consumer as they come in different vapor flavors including mint, coffee, chocolate and various fruit flavors.

New rule proposed for e-cigarettes

In April 2014, the FDA put forth a new rule that would, under the Family Smoking Prevention and Tobacco Control Act of 2009, extend its authority to new tobacco products. Currently cigarettes, cigarette tobacco and smokeless tobacco fall under the agency’s purview. The proposed rule would empower the FDA to regulate, among other tobacco products, e-cigarettes. Under the new rule, e-cigarettes would be regulated under the same provisions that apply to conventional cigarettes such as: the ban on sale to minors and distribution of free samples, marketing of new products only after FDA review, registration of all products with FDA, submission of ingredient list to the FDA and reporting harmful ingredients.

FDA’s analysis of e-cigarettes

So why is the FDA concerned about e-cigarettes? Apart from the worry that the younger generation would be drawn to smoking, there are scientific concerns as well.  In 2009, the agency studied both the cartridges and entire e-cigs of two leading e-cig makers, and analyzed them for nicotine content and other tobacco derived chemicals.

The results indicated a lack of quality control in the manufacturing processes of e-cigs. E-cigs marketed as nicotine-free had small amounts of nicotine in their e-liquids. Cartridges indicating the same nicotine content on their label emitted vapors with different amounts of nicotine. Diethylene glycol, a known ingredient in antifreeze, was found in one of the 18 cartridges tested. Tobacco specific nitrosamines (TSNAs) which are carcinogenic, were found in half of the 18 cartridges. Additionally, tobacco specific impurities, which can prove hazardous to humans, were found in many of these cartridges.

Testing e-cigarettes to ensure their safety

The yet unknown risks of e-cigs and the current non-regulation of these products have propelled the FDA to propose the above-mentioned new rule. E-cigs are claimed to be “safer” by some, promoting the notion that smoking e-cigs is harmless. Even smokers are increasingly switching from conventional tobacco products to e-cigs to aid them in quitting. Hence the escalating use of e-cigs has prompted the FDA to require e-cig makers to report product composition and any hazardous ingredients before these products can be sold to consumers. In fact, a few e-cig makers have already begun characterizing their e-liquids; one even offering consumers the option to receive free batch reports of their product so they can know the exact composition of the e-liquid.

Characterization of the e-liquid and vapor will include testing for nicotine content, nitrosamines and other volatile organics, and heavy metals. This can be easily achieved by analytical chemistry methods using GC/MS, HPLC-UV and ICP-MS. For example, nitrosamines and other volatile organics can be released in the vapor as degradation products of the e-liquid. Forced degradation studies i.e. exposing the e-liquid to extreme heat, light, oxidation and acidic conditions for extended periods of time to represent the worst-case scenario, would “force” degradants to come out. These degradants can then be identified and analyzed by GC/MS. Short-term (1 month) and long-term stability studies (6 months-1 year) can also be used to find out if the e-liquid is degrading over time.

Heavy metals can also leach out of the metal components of the e-cigarette into the vapor inhaled by the consumer. A commonly used heavy metal in e-cigarettes is tin, which makes up solder joints in the cartridge. Tin can be cytotoxic and when inhaled as part of the e-cig vapor, will directly reach the respiratory system of the user. In this case, ICP-MS can be used to detect the presence of even trace amounts of heavy metals and quantify them.

To conclude, the FDA is concerned about the potential hazards of e-cigarettes which prompted it to propose new regulations. To prove the safety of their products in marketing applications, manufacturers of e-cigarettes would benefit from performing rigorous tests such as degradation studies, stability studies, and analyses of degradants and heavy metals.

Pacific BioLabs performs testing of devices, including analytical chemistry. More information on our services can be found here:


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