There are two answers to the question - Why is plastic so bad? The first answer is the number of toxic chemicals used to make plastic. The second answer is that plastic is not stable. The toxic chemicals in plastic easily leach and evaporate into your air, water and food.
A single plastic part may be made up of 5-30 different chemicals. The exact chemicals used are considered trade secrets and are not disclosed.
What is known is that many of the chemicals used to make plastics, the additives, preservatives and monomers, aren’t chemically bound to it. That means they evaporate and leach easily from plastic.
Take polystyrene for example. Polystyrene is used to make food containers, plates and cups that are tough to avoid when you order take out or attend a barbecue.
Studies have found
that at room temperature styrofoam containers release numerous VOCs
into the air, including the carcinogens styrene, benzaldehyde,
benzene and toulene.
And there's really no such thing as a safe plastic. All types of plastics release chemicals that disrupt your endocrine system and cause cancer. These include: