The tobacco industry has investigated and patented technologies that would reduce the substances in cigarette smoke that cause cancer, heart disease and emphysema. Patented innovations which could lead to safer cigarettes include: (1) the addition of catalysts to cigarettes to reduce carbon monoxide and nitrous oxides-- similar to the catalytic converters used to clean motor vehicle exhausts. If used, this approach could reduce the burden of heart disease. (2) manufacturing processes that would reduce the levels of at least one nitrosamine in smokers' lung tissue, thus reducing the incidence of cancer. (3) chemical filters that would remove large quantities of hydrogen cyanide and hydrogen sulphide while also removing acetaldehyde. This would help to reduce respiratory illnesses.
Smoker risk could be reduced by (1) modifying the cigarette to reduce retention of smoke in the lung, or (2) by increasing smoke irritation to reduce depth of inhalation and thus resulting absorption.
Consumers have a basic right to expect that producers make their products as safe as they reasonably can. Even in the unique case of tobacco, where it is assumed and accepted that the product will cause great harm to its users, the smoker should still expect the manufacturer to reduce harmfulness of the product if this is possible. Case law dating back to 1932 shows that there is a general duty of care by manufacturers of goods towards the user whereby the product should be "free from defect likely to cause injury to health". Furthermore, there is a continuing duty on the manufacturer to safeguard the user from his product and to take into account new knowledge. Although tobacco products are exempted from most consumer protection legislation this does not absolve the tobacco industry of all legal and moral responsibility.
Possible reasons for the tobacco companies' reluctance to make safer cigarettes are revealed by their own internal records. Confidential tobacco industry documents released during litigation in the United States show that 'safe' cigarettes created the legal and marketing problem of admitting that the existing products were 'unsafe'.