The ETS from cigars and cigarettes contains many of the same toxins and irritants (such as carbon monoxide, nicotine, hydrogen cyanide, and ammonia), as well as a number of known carcinogens (such as benzene, nitrosamines, vinyl chloride , arsenic , and hydrocarbons). Because cigars contain greater amounts of tobacco than cigarettes, they produce greater amounts of ETS.  There are, however, some differences between cigar and cigarette smoke due to the different ways cigars and cigarettes are made. Cigars go through a long aging and fermentation process. During the fermentation process, high concentrations of carcinogenic compounds are produced. These compounds are released when a cigar is smoked. Also, cigar wrappers are less porous than cigarette wrappers. The nonporous cigar wrapper makes the burning of cigar tobacco less complete than cigarette tobacco. As a result, compared with cigarette smoke, the concentrations of toxins and irritants are higher in cigar smoke. In addition, the larger size of most cigars (more tobacco) and longer smoking time produces higher exposures to nonsmokers of many toxic compounds (including carbon monoxide, hydrocarbons, ammonia, cadmium, and other substances) than a cigarette. For example, measurements of the carbon monoxide (CO) concentration at a cigar party and a cigar banquet in a restaurant showed indoor CO levels comparable to those measured on a crowded California freeway. Such exposures could place nonsmoking workers attending such events at significantly increased risk for cancer as well as heart and lung diseases.