HONOLULU (HawaiiNewsNow) - University of Hawaii Cancer Center researcher Pallav Pokhrel said two ingredients manufacturers mix in E-cigarette liquids are of particular concern.
"They usually like to mix propylene glycol and vegetable glycerin." he said.
When propylene glycol and glycerin are vaporized they produce formaldehyde. a gas that's used in embalming fluid and building materials. Formaldehyde is a known human carcinogen.
"It seems like it becomes dangerous when the E-liquid is heated at a high temperature, with high voltage, and when the E-liquid is dripped directly to the heating coil," he said.
Pokhrel said E-liquid also consists of small amounts of heavy metals. The contaminants differ from liquid to liquid.
He calls that "the scary part" because it's not known how inhaling heavy metals may be affecting consumers. E-liquids also hold varying doses of nicotine. Organic compounds give them their flavors.
"When flavorings are used in food that we eat, most of them are harmless, but we don't know what happens if we breathe them," Pokhrel said.
E-cigarettes come with pre-filled cartridges or a tank system. A pocket-size vaporizer is the newest invention in a rapidly evolving industry.
"The most important thing is to impose some sort of quality control over this product so a standard set of products is available in the market," he said.
Pokhrel said another three-years worth of study is needed before the health affects of E-cigs may become evident. The U.S. Food and Drug Administration is relying on some of his research.