The frame work is made of steel. The outer fabric is a PEVA material which I believe is a lower toxicity than PVC;
According to the Healthy Building Network, PEVA is polyethylene vinyl acetate and is a plastic and a vinyl. In fact there are several types of vinyl - ethylene vinyl acetate (EVA), polyvinyl acetate (PVA) and polyvinyl butyral (PVB) on top of both PEVA and PVC.
We already know that PVC stands for polyvinyl chloride and the Healthy Building Network further breaks down why PVC is so toxic. The C stands for chloride or chlorine and that is what is responsible for the harmful dioxins that PVC emits.
So can we then assume that since there is no C in PEVA that it is non-toxic? The Healthy Building Network again:
Absence of chlorine alone does not make these other vinyls the final answer in the search for green polymers. There are still plenty of toxic challenges and untested chemicals in the life cycle of any petrochemical product. As is the case with most other polymers competing with PVC, however, the weight of available evidence indicates that the absence of chlorine in the formula will generally render the lifecycle environmental health impacts of PVB and the other vinyls less harmful than PVC and initial study is bearing this out.
And the Center for Health, Environmental and Justice points to a study on EVA, and other PVC alternatives (PDF), that states that “…EVA does not require phthalate additives to achieve flexibility…” Phthalates, as you’ll recall are the other culprits in PVC that leads to its toxicity. EVA has also been touted as an alternative to PVC for use in children’s toys including teething rings and PEVA has also found its way into sandwich wraps.
I have grow tents, but these would be a convenient addition for mothers or breeding projects. Both the moms and the breeding projects need minimal light so I think the heat would be quite manageable, I certainly dont think that it would be over ambient temps by enough to start breaking down polymers but Im not certain. You do raise a good point though, thanks for your input.-S0uP