Those worried about lead solder paste in a fridge might be terrified to learn that the coils in the freezer compartment are sometimes lead solder and you have that sitting 24/7 with air and moisture blowing over your food. You also have millions of homes with copper pipes and lead solder .
Lead bonded to a pipe is different than the unused portion sitting in your fridge liable to come into contact with food or hands. The coil is not in contact with anyone/anything other than the air, and unless made airborne by abrasion or some other outside action, lead will not become airborne by itself. While I'm not really concerned about degassing or anything of the sort, and that even if there was leaded solder residue on the container that can possibly transfer to food, I am concerned about accidental ingestion.
It is not good practice, or wise, to keep inedibles compounds in an edible food storage.
While you or I may be capable of deciphering that that is not for consumption... A family member, friend, drunk roommate, etc etc etc, maybe incapable of deciphering that (especially in late night fridge runs).
Your leaded solder is not going to beat up your veggies. But if you live with others, do not chance it. Children are the worst when it comes to do not touch. I should know, I was one of them.