A Cigarette filter is an element of an cigarette, in addition to cigarette paper, capsules and adhesives. The filter may be made out of cellulose acetate fibre, paper or activated charcoal (either as a cavity filter or embedded to the cellulose acetate). Macroporous phenol-formaldehyde resins and asbestos have also been employed in cigarette filters The acetate and paper get a new particulate smoke phase by particle retention (filtration), and finely divided carbon modifies the gaseous phase (adsorption). Filters is effective in reducing “tar” and nicotine smoke yields up to 50%, with a greater removal rate for other classes of compounds (e.g., phenols), but you are ineffective in filtering toxins including co. Most factory-made cigarettes are equipped with a filter; people that roll their own can buy them from your tobacconist.

Cellulose acetate is created by esterifying bleached cotton or wood pulp with acetic acid. From the three cellulose hydroxy groups intended for esterification, between two and three are esterified by managing the quantity of acid (degree of substitution (DS) 2.35-2.55). The ester is spun into fibers and formed into bundles called filter tow. Flavors (menthol), sweeteners, softeners (triacetin), flame retardants (sodium tungstate), breakable capsules releasing flavors when needed, and additives colouring the cigarette smoke may be included with cigarette filters. The five largest manufactures of filter tow are Hoechst-Celanese and Eastman Chemicals in the United States, Rhodia Acetow in Germany, Daicel in Japan, and Courtaulds in the United Kingdom.

Starch glues or emulsion-based adhesives bring gluing cigarette seams. Hot-melt and emulsion-based adhesives can be used filter seams. Emulsion-based adhesives can be used for bonding the filters on the cigarettes.

Cellulose acetate is non-toxic, odorless, tasteless, and weakly flammable. It’s resistant to weak acids and is largely stable to mineral and fatty oils in addition to petroleum. It is biodegradable as well as the raw materials are a renewable natural polymer likely to find application for other uses later on. Smoked cigarette butts contain 5-7 mg nicotine (about 25% with the total cigarette nicotine content), children ingesting >2 whole cigarettes, 6 cigarette butts or a total of 0.5 mg/kg of nicotine should be admitted to some hospital. Cellulose acetate is hydrophilic and retains the water-soluble smoke constituents, which most are irritating (acids, alkali, aldehydes, and phenols), while letting with the lipophilic aromatic compounds.
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