America's Test Kitchen looked into it and it's just not a problem at the temperatures used in sous vide.
There are no issues in terms of taste or plastic leaching or anything of the sort, though if you're really paranoid you can always use Mason jars or silicon bags.
I use reusable food grade silicone bags I bought from Amazon. They are not vacuum sealed but I don't think that matters at all. As long as the portion of the bag containing the food is completely submerged the water pressure is sufficient to seal the bag around the food and ensure even heating in my experience.
I did not research it. The hottest temperature I use is 145F for chicken or pork ribs. Salmon is only 109F. If you have already looked into the use of plastic when cooking, which I haven't, and you know which temperature range is considered dangerous, then those numbers might help you.
There are no issues in terms of taste or plastic leaching or anything of the sort, though if you're really paranoid you can always use Mason jars or silicon bags.