Is polysorbate 80 very toxic?

Not likely. Polysorbate 80 is used in a variety of foods (ice cream, for example) and cosmetic products. There is a theoretic risk for developing increased blood clots - but it is used as food additive both in europe and usa - the details of this product is http://www.Chservice.Ru/download/crills%20and%20crillets.Pdf.
Moderately toxic. I consider polysorbate 80 moderately toxic; while occasionally eating it will not kill you, it may be a carcinogen, aggravate colitis, cause allergies, aggravate cardiovascular disease etc. It depends on how much you ingest but it's best to minimize all processsed foods and emphasize whole organic foods.