Smoking and other tobacco product use is a well-established threat to human health. It is associated with over 80% of deaths from lung cancer, 75% of deaths from chronic lung diseases such as emphysema and chronic bronchitis, 20% of deaths from coronary heart disease and almost 20% of deaths from stroke. Tobacco use is associated with an estimated four million deaths per year world-wide. According to the Centers for Disease Control and Prevention, cigarette smoking is the single most preventable cause of premature death in the United States. Reducing tobacco product use in general and cigarette smoking in particular has been a well-recognized public health goal throughout the world. Of particular concern is preventing teenagers from starting smoking. Nicotine in tobacco is addictive and this addiction occurs in most smokers during adolescence. Before age 18, most adult smokers in the U.S. had tried their first cigarette and over 50% of them had become daily smokers. NicAlert™ measures levels of cotinine, a metabolite of nicotine widely regarded as the best biomarker for exposure to tobacco in both smokers and nonsmokers. Unlike nicotine itself which the body rapidly metabolizes, cotinine has a relatively long half-life in the body, averaging 18 to 20 hours. It is secreted in both urine and saliva. It is a more sensitive and specific biomarker for smoking status than carbon monoxide, which is inhaled with tobacco smoke, and unlike carbon monoxide, can also be used with other tobacco products such as chewing tobacco.