People on low-salt diets must consume salt supplements to avoid becoming ill. As a gas, chlorine is very hazardous. I as a poison gas. When dissolved in the moist mucous membranes of the nose and throat, it can cause irreversible damage that can be lethal. Because of this hazard, chlorine gas is most often used close to where it is made, thus avoiding risks associated with transportation of the gas in bulk.
Chlorine is one of the most important basic chemicals in the chemical industry.
A number of important products are made from chlorine gas. One of the greatest benefits of chlorine to humans has been its use in the disinfection of water. With the industrial revolution and an increase in urban populations, epidemic diseases became a major threat to human health. In 1848, cholera appeared in London, England and claimed 14,600 lives within two years and a further 10,600 lives in the epidemic of 1854. The spread of the disease was linked to the contaminated water supply, and the control of the disease was hindered by the lack of adequate sewers.