system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: ELI5: how does odor transfer through plastic? And does it mean the object giving off the odor is technically penetrating the plastic?
gpt
Yes, any time you smell something *actual pieces of that substance are going into your nose*. Smell is physical contact between molecules and sensory cells in your nose.

If you smell something through a wrapper or bag, yes, the odoriferous molecules are penetrating through the plastic. The molecules we smell tend to be pretty small and light (hence they are able to come off the substance and float in the air) and plastics are quite permeable compared to say, glass.