I bought a grow tent that was 48" x 48" x 78", I beleive, and the inside was white vinyl. It smelled like plastic, but I thought it couldn't be that bad and after I got the fans and carbon filter going, you couldn't hardly smell anything.
Well, I was a first time grower and after trying multiple times for about 6 months, I never got any plant over like 3" tall and I was doing everything totally by the book. The main problem was yellowing leaves I just could not ever fix. I tried everything, went from CoCo to Fox Farm Ocean Forest soil, from General Hydroponics nutes to Fox Farm nutes, I had 4 - 4' T5 flouros then went to a 250W HPS, and still no improvement, I spent a fortune on seeds as well.
Out of desperation, I got a another tent, a 36 x 20 x 60 with the silver reflective mylar interior, which, by the way, didn't smell at all. And guess what? I hung the HPS light in the center and hung the T5's vertically near my pots, and I've got three plants that seem to have grown every time I look at them. I had a few issues with heat right at first and went too easy on the nutes to be safe which caused 2 yellow leaves on one plant in the beginning, but with the heat in check and the correct pH, I'm going full strength on Fox Farm nutes and they're growing like weeds, I've got buds and leaves covered in crystals.
So having said all that, I'm sure not all white vinyl ones are toxic, and maybe some mylar ones are, but I'd say stay away from the white vinyl ones.