More than 5,000 smoke constituents (or emissions) have been identified in tobacco smoke to date. Approximately 100 smoke constituents have been identified by public health authorities as likely causes of smoking related diseases such as lung cancer, heart disease, and emphysema. These constituents include carbon monoxide (CO), benzene, heavy metals (e.g. lead, cadmium), and tobacco specific nitrosamines.
Many countries require cigarette manufacturers to print the per cigarette yields of tar, nicotine, and CO on cigarette packs. Some countries, including all of the European Union countries, also have established ceilings--maximum limits--for tar, nicotine, and/or carbon monoxide yields. With the exception of a handful of countries such as the Netherlands, very few countries regulate tar, nicotine, and carbon monoxide yields in other smoked tobacco products such as roll-your-own tobacco.
Per cigarette tar, nicotine, and carbon monoxide yields are measured by standardized machine test methods. The most widely used test method is the method of the International Organization for Standardization (the “ISO method”). Another method is the more intensive method developed by Health Canada.
In addition to requiring testing and reporting of per cigarette tar, nicotine, and carbon monoxide yields, a few countries, including Canada, Brazil and Taiwan, require testing and reporting of other smoke constituents on a per cigarette by brand basis. These countries require testing of approximately 45 smoke constituents that have been identified as likely causes of tobacco-related diseases.
No country has imposed ceilings or maximum smoke yields for smoke constituents other than tar, nicotine, or carbon monoxide. However, a few public health advocates have proposed maximum yields for a limited range of smoke constituents, including tobacco specific nitrosamines.
Articles 9 and 10 of the Framework Convention on Tobacco Control concern regulation of tobacco product emissions (smoke constituents). Accordingly, the Conference of Parties Working Group on Articles 9 and 10 is developing guidelines for the testing, measuring, and regulation of tobacco smoke constituents. In August 2008, the Working Group identified several “priority” emissions and estimated that it would take five and a half years to develop and validate test methods to measure them.
Regulating Tar, Nicotine, and Carbon Monoxide Yields
Manufacturers should be required to report the tar, nicotine, and carbon monoxide yields in the smoke of each of their brands on an annual basis. We believe that the ISO test method should continue to be used as the standard test method for these reports. However, it should be understood that neither the ISO method, nor any other machine-based measurement can, or is meant to, accurately represent human smoking behavior in all cases and under all circumstances.
We would also support requiring dual testing under both the ISO test method and the more intensive Health Canada test method. Based on available data, we believe that the Health Canada method provides a potential upper range for tar, nicotine, and carbon monoxide yields and is an appropriate complement to the current ISO method. Requiring testing under both test methods would reflect a range of smoke intake, better illustrating the wide variability in tar, nicotine, and carbon monoxide intake, depending upon how an individual smokes a cigarette.
We do not oppose tar, nicotine, and carbon monoxide ceilings as long as they are technically feasible and are not intended to make cigarettes unacceptable to adult smokers. We note that public health authorities take the position that reducing machine based yields of tar, nicotine, and carbon monoxide does not reduce the adverse health effects of smoking. Public health authorities have raised additional questions about nicotine yields. For example, the WHO’s Advisory Committee on Tobacco Product Regulation stated, “With respect to nicotine, it remains uncertain at this time whether public health would be better served by increased or decreased levels of nicotine per unit (e.g., cigarette) and further study of this issue is required.” 
Regulating Other Smoke Constituents
We support regulation requiring manufacturers to report by-brand information on yields of other smoke constituents that have been identified as likely causes of tobacco related diseases. Knowing the yields of a range of smoke constituents in conventional lit-end cigarettes is an important step in developing a better understanding of the relationship between smoking and disease and, most importantly, in establishing a baseline against which to assess novel products that could have the potential to reduce the risk of disease. However, before elaborating specific testing and reporting requirements, several fundamental issues must be resolved.
First, there should be agreement among the scientific and public health community on the most important constituents to regulate.
Second, the analytical methods for measuring individual constituents must be developed and validated.
Third, only a handful of laboratories in the public or private sector have the ability to test for smoke constituents other than tar, nicotine, and CO. The development of adequate laboratory resources therefore is necessary.
Since so little is known about how individual constituents or groups of constituents impact the development of smoking related diseases, it is impossible at this point to accurately predict the impact – if any – that reducing, or selectively eliminating, a specific smoke constituent or groups of smoke constituents will have on risks associated with smoking.
We believe, therefore, that it would be premature to impose mandatory ceilings on other smoke constituents.
Regulating Smoke Constituents in Other Tobacco Products
As with other kinds of regulation, regulation of smoke constituents should apply to other tobacco products such as roll-your-own tobacco products. The scientific and regulatory communities should establish regulations governing other tobacco products in order to ensure that consumers receive accurate information across all tobacco product categories, especially with regard to other tobacco products that are marketed and used as substitutes for manufactured cigarettes. Creating equivalent regulations will permit manufacturers to compete on a level playing field, ensuring that regulations do not create an unfair advantage for one product category over another.
 World Health Organization, Scientific Advisory Committee on Tobacco Product Regulation Recommendation on Tobacco Product Ingredients and Emissions