@V_ In college I worked in a physics lab—what I was doing exactly was complicated, but I was using ethylene glycol, which is the acutely toxic compound that makes antifreeze viscous and also happens to make it taste sweet. Then I noticed that the orange soda I was drinking contained propylene glycol, which is a nearly identical molecule, similarly sweet and viscous (it gives the soda “creamy” mouthfeel) but is apparently perfectly safe. I believe I may not have finished the soda. Let’s say it concerned me.