Hmmm. Stop bath is basically just vinegar, and the same soldium sulfite we use in the darkroom is what fastfood restaurants add to salads and bottlers add to wine to slow oxidation. But harmless? Some people are deathly allergic to sulfites, and personally, I prefer to use kitchen vinegar rather than stop bath to make my salad dressing. Ya just never know. Ever look at the fine print of what goes into an ordinary box of table
salt? Same brightener pigments they use in paint. But I wouldn't pour paint on my breakfast eggs in the morning if I ran out of salt in the shaker.