I have been doing a lot of research lately on the additive the cigarette companies use to make the "safer" cigarettes. The coalition fighting for the legislation refuses to disclose the information, as well as the cigarette companies, but through perseverance, I have found that the chemical used is called sodium silicate. Inhalation of the chemical can cause severe irritation of mucous membranes and upper respiratory tract. Symptoms may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting. High concentrations may cause lung damage.