my dog is eating plastic stuff

You should sop him from eating things that are not edible if chocks Lay the dog down on its back and push upwards quickly and sharply into the chest cavity. Then once you have the object expelled if the dog doesn't start breathing on its own you do CPR. That is laying the dog on its right side, pressing on the chest just under the front leg, in a pumping motion. Hold the snout closed and blow one breath of air into the dogs mouth and nose. You have to cover both mouth and nose in order to keep the air from escaping. See if the chest rises, then go back to pumping on the chest (I do four pumps and one breath. everyone differs) repeat until the dog starts to breath on its own. Do not continue you can hurt the dog.

This is just a mere hypothesis, in case your dog is a puppy. Just like in baby humans, they tend to chew random things especially rubbery things because of the new growth of tooth/teeth. But your dog's case is different because he chews and eat the plastic material which can be hazardous. I suggest that you put away all those stuffs, also you can check the pet shop/grocery for alternative toys that are edible.