At first that wigged me out but then I thought I often did I smoke my cigs down to the ....? Ever look at the bottom part of your filter? Heck the minute you take a drag the filter turns brown. Figure my carts only look like this after a week or more of vaping and still nothing near as bad as a cig filter. Atty wicks don't look much better and burnt fluval of polyfill......I am not going to loose sleep over it unless they discover the damn things are full of asbestos!