Health Letter, July 2014
By Sarah Sorscher, J.D., M.P.H.
In May, The New England Journal of Medicine (NEJM) published a report by a physician who had treated a 10-month-old boy rushed to the hospital with vomiting, a racing pulse and loss of muscle coordination. The child had ingested a “small” amount of mint-flavored liquid nicotine, which had been sold by a local e-cigarette shop in a bottle hand-labeled “18 mg” (18 milligrams per milliliter). Fortunately, the boy made a full recovery.
Like the physician who reported this case in the NEJM, doctors and public health officials across the country have begun sounding alarms about a previously little-known risk: serious, sometimes potentially fatal poisoning from liquid nicotine produced for and found in e-cigarettes.
E-cigarettes were not marketed in the U.S. prior to 2007, but in recent years, their use has increased as a popular — and relatively unregulated — alternative to cigarettes and other traditional tobacco products.
This new popularity has spurred a dramatic increase in the number of poisonings related to liquid nicotine. The Centers for Disease Control and Prevention (CDC) reported in April 2014 on the three-year rise in nationwide poisoning cases from liquid nicotine and e-cigarettes. Its findings showed that poison control centers reported just one case of nicotine poisoning in September 2010, the month the CDC began tracking this information. By February 2014, centers across the country were receiving more than 200 nicotine poisoning calls per month.
Higher poisoning risk with e-cigarettes
E-cigarettes are often presented as a safer alternative to traditional cigarettes made from tobacco. Yet when it comes to poisoning risk, e-cigarettes present many new dangers, for both adults and children.
The liquid used in e-cigarettes is generally a combination of nicotine, flavorings and solvents. Unlike the nicotine in traditional cigarettes, which is absorbed by inhalation of smoke or ingestion only, liquid nicotine can be absorbed through contact with the skin or eyes. The New York Times recently reported the case of a Kentucky woman who was admitted to the hospital with heart problems after her e-cigarette broke in her bed, allowing the nicotine liquid to spill and then be absorbed through her skin.
Concentrating nicotine in liquid form makes it much easier to receive a toxic dose. The concentration of liquid nicotine products varies widely, from as low as 1.8 percent to as high as 10 percent. A single teaspoon of a 1.8 percent nicotine solution, a common concentration sold for e-cigarettes, could kill a 200-pound adult (and easily a much smaller child). To get the same dose of nicotine, a person would have to smoke over 30 traditional tobacco cigarettes.
Because e-cigarettes are not currently regulated, the actual concentration of liquid nicotine in a product may be different from what is stated on that product’s labeling. One study by the Food and Drug Administration (FDA) in 2009 found that nicotine concentrations in e-cigarette liquid varied as much as 1.6-fold, even when comparing different cartridges of the same brand. (Nicotine content in vapor released by e-cigarettes also varies, with one study finding a 30-fold variation between puffs.)
Certain e-cigarette systems may also deliver dangerously high inhaled doses or open up opportunities for accidental skin exposure or ingestion. Initially, many e-cigarettes were disposable devices that looked like conventional cigarettes, some fully disposable and some with standardized, replaceable cartridges. More recently introduced are larger, reusable gadgets that can be refilled with liquid nicotine sold separately in small vials, liters or even gallons.
Some e-cigarettes, popularly known as “tank systems,” work by superheating liquid nicotine, leading to a more potent dose of nicotine (as well as other dangerous chemicals). Users can also modify the systems by “dripping” liquid nicotine directly onto the heating element, again with the goal of increasing the heat and potency of the vapor. These new methods for increasing potency also raise the risk of nicotine overdose.
New and disturbing poisoning trends
Traditional tobacco cigarette poisonings overwhelmingly involve ingestion of cigarettes by children. By contrast, a surprising number of e-cigarette and liquid nicotine poisonings over the past several years have occurred in adults.
The CDC found that about 42 percent of poisoning reports since 2010 have involved adults over the age of 20. This may reflect the fact that many e-cigarette users are not aware that nicotine poisoning can occur through inhalation or skin exposure, risks generally not present with tobacco cigarettes. Over one in six poisoning cases result from nicotine inhalation, and close to one in seven result from exposure through the skin or eyes.
To date, only one poisoning case has resulted in death: A 29-year-old man committed suicide by injecting himself with nicotine liquid. He was rushed to the hospital and resuscitated. However, he developed uncontrollable seizures and was eventually declared brain-dead.
Many poisoning cases result in hospitalization. The American Association of Poison Control Centers reported that out of 438 cases of e-cigarette and liquid nicotine poisoning reported in 2012, 112 required treatment in a hospital or other health care facility.
While adults are at risk from liquid nicotine poisoning, the risk is particularly troubling for children, who experience toxic effects at lower doses and are also more likely to unknowingly drink liquid nicotine. Liquid nicotine for e-cigarettes often comes in brightly colored bottles with attractive flavorings such as cherry, chocolate and bubble gum, making it more appealing to children.
“We have been lucky so far that none of the accidental overdoses have resulted in death,” said Dr. Michael Carome, director of Public Citizen’s Health Research Group, which has been active in the past in pushing for stronger tobacco regulation. “It’s only a matter of time before someone, child or adult, accidentally receives a fatal overdose.”
Regulation on the horizon?
Some members of the e-cigarette industry have expressed an interest in limited regulation, including requirements for warning labels and childproof liquid nicotine bottles and containers.
The FDA recently proposed a new rule that would extend the agency’s authority under the 2009 law known as the Tobacco Control Act to include regulation of e-cigarettes. The FDA has announced plans to restrict the sale of e-cigarettes to minors, but it is not clear how the new regulations will address poisoning risks.
“We are seeing the beginnings of what could become a massive public health problem if current use and accidental exposure patterns related to liquid nicotine products continue,” Carome said. “Strong, targeted regulation is the only way to curb this disturbing poisoning trend.”
 Juntti M. How E-Cigarettes May Harm Your Health. Men’s Journal. http://www.mensjournal.com/health-fitness/health/how-e-cigarettes-may-harm-your-health-20140520.
 Westenberger BJ. Letter to Michael Levy, Supervisor Regulatory Counsel, CDER, Office of Compliance, Division of New Drugs and Labeling Compliance, re: the Evaluation of e-cigarettes. Food and Drug Administration, Center for Drug Evaluation and Research. May 4, 2009.
 Chatham-Stephens K, Taylor E, Mestrom P, et al. Calls to poison centers for exposures to electronic cigarettes – United States, September 2010 – February 2014. MMWR. April 4, 2014;63(13):292-293.
 Mowry JB, Spyker DA, Cantilena LR, et al. 2012 Annual report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 30th annual report. Clin Tox. 2013;51:949-1229.
 Food and Drug Administration. FDA proposes to extend its tobacco authority to additional tobacco products, including e-cigarettes. April 24, 2014. http://www.fda.gov/newsevents/newsroom/pressannouncements/ucm394667.htm.