Electronic Cigarettes (e-cigarettes) were invented by a Chinese pharmacist who watched his father die of lung cancer but was unable to stop smoking himself. He reasoned that if the nicotine that smokers crave could be delivered via a less hazardous method, millions of lives could be saved. His invention vaporizes a liquid that contains a small amount of nicotine—typically less than 2%. The vapor is created using the same type of chemical used in artificial fog machines.
By eliminating the combustion involved in smoking tobacco cigarettes, e-cigarettes avoid the lung damage caused by tar and partially burned particles of tobacco and cigarette paper. Because the poisonous gasses such as carbon monoxide are also eliminated, the risks of heart attacks and strokes are reduced. Tobacco contains some naturally-occurring substances that can cause cancer, and burning the tobacco creates additional carcinogens and toxic chemicals. E-cigarettes contain no tobacco and don’t burn anything at all. They use the same pharmaceutical-grade nicotine that is found in medicinal nicotine products such as the patch, lozenges, gum, as well as nasal spray and oral inhalers.
The first scientific study to show that the vapor emitted by e-cigarettes contains nothing likely to harm users or bystanders was conducted by Dr. Murray Laugesen of Health New Zealand who tested e-cigarette vapor for over 50 cigarette smoke toxicants. He reported at the April 2009 Society for Research on Nicotine and Tobacco Conference that e-cigarette users do not inhale smoke or smoke toxicants. His conclusion was, “E-cigarettes are akin to a medicinal nicotine inhalator in safety, dose, and addiction potential.”
In July, 2009 the US Food and Drug Administration (FDA) lab report on testing of 18 e-cigarette samples revealed that the only potentially harmful thing the agency could find in the vapor was tiny trace of a minor tobacco alkaloid. However that chemical is neither toxic nor carcinogenic. That fact was not highlighted in the Agency’s press conference statements. Rather, the agency pretended that harmless amounts of chemicals detected in the unvaporized liquid presented a serious danger to public health.
In response to the FDA’s public relations attack, several e-cigarette companies immediately hired external laboratories to conduct toxicology testing on liquid and vapor. Dr. Michael Siegel of Boston University School of Public Health, along with Berkeley’s Dr. Zachary Cahn, reviewed the results of 16 studies (including the FDA lab report) and statetd, “Although the existing research does not warrant a conclusion that electronic cigarettes are safe in absolute terms and further clinical studies are needed to comprehensively assess the safety of electronic cigarettes, a preponderance of the available evidence shows them to be much safer than tobacco cigarettes and comparable in toxicity to conventional nicotine replacement products.”
Now, two more recent studies have confirmed that all trace chemicals that can be detected in vapor are well below the level that could cause even minimal harm.
A study by German researchers has been accepted for publication in the scientific journal, Indoor Air. The researchers compared the volatile organic compounds (VOCs) and ultra-fine particles in smoke to measurements of the same substances in electronic cigarette vapor.
Test subjects were seated in an 8 cubic meter stainless steel test chamber. Air in the chamber was tested after 20 minutes to determine the air quality with no smoke or vapor present. The subject was then handed an e-cigarette containing an apple flavored liquid with no nicotine (Liquid 1) through a sampling port. The subject was instructed to take six 3-second puffs, with a delay of 60 seconds between each puff. Researchers began testing the air starting with the 4th puff and continued sampling for 15 minutes. This process was repeated with two other e-cigarette liquids, both containing 1.8% nicotine. One was apple flavor (Liquid 2) and the other was tobacco flavor (Liquid 3.) After the last e-cigarette was removed from the chamber, the subject was handed a lit conventional tobacco cigarette. The same sampling procedure was used.
A table in the article reported on concentrations [μg/m³] of selected compounds during the 8 m³ emission test chamber measurement one type of e-cigarette, using three different liquids, and conventional cigarette smoke.
Twenty chemicals were found in conventional tobacco cigarette smoke. Only six of these chemicals were found in e-cigarette vapor and the highest quantities were found in Liquid 3 vapor.
The researchers reported the quantities in micrograms per cubic meter of air (mcg / m3) and concluded that “passive vaping” must be expected from the consumption of e-cigarettes. They also stated ominously that “The consumption of e-cigarettes marks a new source for chemical and aerosol exposure in the indoor environment.” However, they failed to provide any guidance regarding the danger level to bystanders from this “passive vaping.”
Many world governments set occupational exposure limits for chemicals. These values can be used to estimate the level of danger presented by chemicals in vapor. In the U.S., these limits are expressed in parts per million (PPM) and/or in milligrams per cubic meter (mg / m3.)
Table 1 provides a comparison of the highest quantity of each chemical measured to the occupational exposure limit. The quantities measured by the researchers are converted to mg /m3 to facilitate a comparison with the exposure limit. The columns contain the following information:
[See Table 1 image]
*The US has not set an exposure limit for Isoprene. The limit set by Poland was used as the “Exposure Limit mg / m3” value.
Of note is the fact that the quantities measured for conventional cigarette smoke for these chemicals ranged from two to forty times higher, yet the quantities measured were so tiny that, even in smoke, none met or exceeded the Exposure Limit.
Concerned that some compounds that they expected to measure in the chamber tests were missing and/or present in barely detectible amounts, the researchers decided to measure VOCs directly in exhaled breath. For this part of the experiment, each e-cigarette consumer was asked to exhale one puff into a 10 L glass chamber. Five of the nine chemicals measured in this “captured” exhaled vapor are not considered toxic by inhalation, so there is no set occupational exposure limit. Of those chemicals that do have an exposure limit, all were present in the samples at a safety margin of at least 90%. The safety margin is assumed to be 100% for VOCs with no Exposure Limit. The findings are shown in Table 2.
[See Table 2 Image]
Some non-smokers have expressed concern about inhaling nicotine should they be exposed to exhaled vapor. It should be particularly comforting to observe that the quantity of nicotine in a puff of captured exhaled vapor too small--even if inhaled directly by a bystander--to have any health effects whatsoever. If a bystander were to lock lips with a user after each inhaled puff and take in the entire quantity of nicotine the user inhales, after 300 puffs the bystander would be exposed to 2.1 mg of nicotine, which is the approximate quantity present in a low-dose nicotine lozenge or piece of gum. At these quantities, nicotine is not a danger to health and does not cause addiction. Furthermore, the nicotine would be delivered much more slowly—at about 1/10 the speed of delivery from gum or lozenges.
However, bystanders concerned about inhaling nicotine are unlikely to lock lips with an e-cigarette user, and since no nicotine was detected in the air samples taken in the stainless steel test chamber, it is apparent that the tiny amount of nicotine exhaled by the user is quickly diluted by mixing with the ambient air. As a result, bystanders are not exposed to nicotine at all.
Another recent study called Clearstream Air compared traditional smoke with electronic cigarette vapor and found nothing in the vapor that presents a danger to the health of users, much less to bystanders. The results are reported at the 14th Annual Meeting of the Society for Research on Nicotine and Tobacco (SRNT) Europe in Helsinki, along with the results of a study that looks at the effect of vapor on living cells.
Despite the mounting scientific evidence that e-cigarette vapor is not hazardous to the health of users or bystanders, some groups such as Americans for Nonsmokers' Rights and American Lung Association lobbyists continue to insist that vapor should be included in laws meant to protect the public from smoke exposure. Calling vapor smoke does not change the physical and chemical properties of either substance. Including vapor in smoking bans encourages smokers to continue lighting up instead of switching to an alternative that could save their lives and reduce health risks of bystanders.