E-cigarettes, even the ones that are plugged into the correct charger and don’t explode, have a problem. Well, their users have a problem. Some former cigarette smokers who are used to flinging butts out the window when they finish a smoke are having trouble letting go of their nasty habit. The trouble is that metal e-cig cartridges are, well, metal, and puncture tires out on the roads.

“We have seen usually one or two [nicotine cartridges] a week puncturing the tire,” the manager of a tire shop told TV station WGAL. The cartridges, which are made out of metal, are much more harmful than a cigarette butt when they land on the road. “When they slash a tire,” the shop manager explains, “they usually leave a pretty big gash in it.”

Unlike a nail, the sharp cartridges don’t leave a simple hole in the tire that can be plugged up. They leave a gash that can’t be patched.

So, smokers, as you use the battery-powered device to break one bad habit, please try to break another. Keep a trash bag in your car for the cartridges.

E-cigarette cartridges puncturing tires [WGAL]