Cling-film used to be heavily plasticised PVC, and I can remember that it was being investigated when I started work. Poly-tunnel greenhouses were also reputed to have killed the plants they were protecting!
PVC must be better now (decades later), but vinyl chloride monomer is a carcinogen and it often takes years of suspicion before the effects are catalogued.
With the life-span of cephalopods being short they are not so likely(?) to suffer noticeably from trace chemicals leached from plastics. I would be more afraid of reef tanks, where phthalates could well upset the algal symbiosis in the corals.
You have to keep your eyes and ears open, and do the best you understand.