You've heard of how plastic ruins the environment; because it's not biodegradable, plastic continues to pollute the oceans. Many animals also die thinking they're full but suffer from a lack of nutrition from the plastic in their stomachs.
But, when you occasionally bite off a piece of plastic from a wrapper as you're eating a sandwich, do you feel the need to spit it out? I will shamelessly say that sometimes I can't be bothered to rummage through my mouth to find that small piece among a sea of chewed food, so I end up swallowing that plastic. How bad could a 1 mm piece of plastic be, anyway?
The good news is that eating a piece of plastic won't mean you will have the same fate as the poor animals that mistake plastic for food. According to Lusher, the plastic will leave your system after a day since it's small and your body tries to get rid of anything that can't be dissolved or used effectively. But, constantly eating plastic or food that is packaged in plastic can leave long-term side effects that you want to avoid.
There are chemicals in plastic that can easily be transferred to your food by microwaving things in plastic, eating canned food lined in plastic lacquer, drinking bottled water, etc. The most commonly used chemical is phthalates, which makes plastics soft and bendable. This is not chemically bound to plastic, so it can get transferred to other things easily.
That's not the worst part. Some problems from ingesting this chemical are premature births, asthma, cancer, miscarriage, male infertility, premature breast development, and abnormal male sexual development. Right now, they don't seem like threats, but they will when you get older.
So, next time you eat plastic—accident or not—you might want to stop yourself. Also, try not to eat things that have been in plastic containers for a long time. Although there won't be a significant change in the short term, you might experience harmful effects later on.