Jan Dell is a former chemical engineer who has spent years telling an inconvenient truth about plastics. "So many people, they see the recyclable label, and they put it in the recycle bin," she said.

Here's why: Not all plastics can be recycled. And if you aren't rinsing out containers and removing labels from those that are, you could be making the rest of the recyclable batch useless.

Ever since, the world has had an almost insatiable hunger for plastics. This is because plastics’ structure—made up of repeating molecular units called monomers, which can be combined and ...