it's not safe. there are ingredients that just dont behave well with plastic tanks. especially citrus flavors, cinnamon flavors, etc. the solution is to buy glass tanks. i buy a lot of juice from mt baker and they keep a list of all their "tank-crackers". some people just get juices that wont crack their tanks, i get tanks that wont crack from my juices.
ive never tried pluid but people said black licorice and i ran. jager is about the only thing i do that tastes like black licorice and i dont drink it because i like the taste.