Did you think the cigarette filter is made out of paper? So did we. Unfortunately, that’s not the case. 60% of the filters consist of cellulose acetate, a type of plastic that degrades very slowly. This process can take several years, and the worst part is that even when we can no longer see the filters, they’re still with us. Just like all other plastics, cellulose acetate breaks down into microplastics that can remain for a hundred years – or more.