Most smokers probably know that their habit compromises their health and that of those inhaling their smoke. The tobacco industry is supplying alternatives to cigarettes — e-cigarettes and vaporisers — as a safer alternative that does not reduce their profits.

But the jury is still out on how healthy the electronic alternatives are.

Nicotine is a highly addictive parasympathetic nervous system stimulant, and the foremost reason for cigarette addiction is its dopamine reward feedback when smokers light up.

The compound hydrogen cyanide is found in cigarettes. According to the National Centre for Biotechnology Information, "cyanide is used in a number of industries and is found at low levels in the air from motor vehicle exhausts. Cyanide is extremely toxic to humans".

Chronic (long-term) inhalation exposure of humans to cyanide results primarily in effects on the central nervous system, it says. Other effects in humans include cardiovascular and respiratory effects, an enlarged thyroid gland and irritation to the eyes and skin.

Another compound in cigarettes is dimethylnitrosamine (DMN). The British Journal of Cancer reports that studies were done on hamsters injected with DMN which "induced malignant haemangioendotheliomata of the liver and kidney, hepatocellular carcinomata, and, in one animal, a cholangiocellular carcinoma".

Malignant haemangioendotheliomata is tuberculosis, hepatocellular carcinomata is cancer caused by the destruction of liver cells, and cholangiocellular carcinoma is a cancerous bile duct tumour. Other carcinogenic compounds in cigarette smoke include carbon monoxide, lead, arsenic and quinoline.

The US Environmental Protection Agency, the US National Toxicology Programme, the US surgeon-general and the International Agency for Research on Cancer have classified secondhand smoke as a known human carcinogen, with about 3,000 lung cancer deaths a year among nonsmoking adults in the US as a result of exposure.

The US surgeon-general estimates that living with a smoker "increases a nonsmoker’s chances of developing lung cancer by 20% to 30%", with some research suggesting that "secondhand smoke may increase the risk of breast cancer, nasal sinus cavity cancer and nasopharyngeal cancer in adults; and increase the risk of leukemia, lymphoma and brain tumours in children".

The Royal College of Physicians says vaping "is unlikely to exceed 5% of the harm from smoking tobacco", and the Cancer Organisation says that most of the harmful chemicals come from "the burning of tobacco leaves" — which are not used in vaporisers and e-cigarettes.

But "popcorn lung" can be a result of electronic smoking.

This references a popcorn factory in Missouri in the 1990s, where several workers suffered irreversible lung damage called bronchiolitis obliterans from the same artificial flavourings used in vaporisers and e-cigarettes.

However, the workers at the popcorn factory inhaled massive quantities of the chemicals diacetyl and acetyl propionylin in powdered form, so the risk factor for the lung condition is not yet measurable in e-liquids.

Formaldehyde is another toxic substance present in electronic smoking devices, but is only dangerous in high concentrations when most or all of the e-liquid has been used and the smoker takes a "dry puff".

The Agency for Toxic Substances and Disease Registry says formaldehyde exposure at a low dose "can result in headache, rhinitis, and dyspnea … and lower respiratory effects such as bronchitis, pulmonary edema or pneumonia.

"Sensitive individuals may experience asthma and dermatitis, even at very low doses. Formaldehyde vapours are slightly heavier than air and can result in asphyxiation in poorly ventilated, enclosed, or low-lying areas."

Dry-puff studies have not been conducted because there is little risk of a user committing to inhaling without any liquid left in the device as this is "repulsive".

Although the nicotine content is far lower than in combustible tobacco products, vaping has, to an extent, been associated with periodontal diseases because of its nicotine content, depending on how regular the user vapes.

A study, titled Secondhand exposure to vapors from electronic cigarettes, in Oxford Journals’ Nicotine and Tobacco Research, found that "the average concentration of nicotine resulting from smoking tobacco cigarettes was 10 times higher than from e-cigarettes", but concluded that "using an e-cigarette in indoor environments may involuntarily expose nonusers to nicotine".

"More research is needed to evaluate health consequences of secondhand exposure to nicotine, especially among the vulnerable, including children, pregnant women, and people with cardiovascular conditions."

The efficacy of e-products as smoking cessation tools is also controversial. A study by the California Tobacco Control Programme concluded e-cigarettes "are not FDA-approved [US Food and Drug Administration] quit smoking devices" (with hundreds of e-cigarette companies bypassing FDA approval).

"They qualify because e-cigarettes are regarded as a ‘safer’ mode of nicotine intake than cigarettes; many use both products at the same time, and never actually quit altogether." This meant that "any potential health benefits are reduced … the cardiovascular risks associated with smoking stay essentially the same and continue to cause significant health problems".

A meta analysis conducted by the US Preventive Services task force concluded that "adult smokers who uses e-cigarettes are 28% less likely to stop smoking cigarettes".

SA’s Department of Health has proposed the Control of Tobacco Products and Electronic Delivery Systems Bill to clamp down on availability and marketing; and restrict smoking (and vaping) in all public areas to mitigate the known health risks associated with smoking and the unknown long-term risks of e-liquid intake.

The Vapour Product Association is preparing to object to these proposed regulatory controls on the grounds they would damage sales and the reputation of its products, because it has been slotted in with manufacturers of cigarettes.

Studies show there is no comparison between the toxicity of tobacco products (cigarettes) and e-liquids (vapes and e-cigarettes), yet nicotine hits and addiction are the primary factor for sales of both.

The bill’s preamble says one form of taking nicotine "encourages" sales of the other and "there should be a precautionary approach to the regulation of electronic delivery systems".