<p><b>About cigarettes. Part 2</b></p> <p><b>Filter</b></p> <p>Filter is intended for reducing smoke quantity and certain components of it that enter smoker's organism. Majority of filters are manufactured of organic fiber - cellulose. Cellulose doesn't have its own taste and us quite firm to keep the form. Along with other elements of cigarettes' construction, such as ventilation, use of filters with various efficiency of filtration allows to achieve various levels of tar and nicotine content and in the end - different flavor strength and aroma strength of tobacco smoke.</p> <p><b>Ventilation</b></p> <p>Cigarette is ventilated in order to reduce level of smoking components, first of all, tar, nicotine and carbon monoxide. All cigarettes are ventilated thanks to natural porosity of cigarette paper; besides, many cigarettes are ventilated through perforation are mixed with smoke that comes from zone of cigarette smoldering. Filter ventilation is the base and obligatory characteristic of cigarettes with low content of tar.</p> <p><b>Smoke</b></p> <p>Tobacco smoke is, perhaps, one of the most complex and more actively studied blends in the world. As many other natural substances, tobacco includes thousands of components (at present moment is found approximately 2500). In process of tobacco burning out depending on temperature and concentration of oxygen are formed approximately 4000 smoking substances. Concentration of their majority is extremely low.</p> <p>The main flow of smoke is smoke that gets in the breathing system of smoker when he inhales, but side flow of smoke is smoke that isolates from smoldering cigarette end.</p>