There is technically no expiration date on cigarettes. The nicotine in the cigarette can create a chemical reaction with polycyclic aromatic hydrocarbon, which causes the smoke to have a bitter and unpleasant taste. That’s also one reason why smoking becomes more physically addictive over time. Older cigarettes will lose flavor quicker because there’s less natural flavoring agents that affect taste.
In general, cigarettes should be disposed of after two weeks or less, due to their increased toxicity from both bacterial and fungal growth as well as increased exposure to other contaminants such as pesticides and heavy metals like mercury and lead (most significant). “The average lifespan of an unprotected cigarette butt is 60 hours through oxidation caused by atmospheric oxygen.
