Don't worry about it- safer's edible, though not particularly tasty.

It just dries on the surface. If you can taste it on harvested and dried stuff, you've used way too much.

It's gotta be the single insecticide most used on OMRI crops- you've probabley eaten some today. The spray mist can be irritating, and some folks are more sensitive than others- but I've only seen anybody have a reaction during multi-acre applications- ie hours of exposure to mist.