At least tell him to stop with the canned ravioli.
I mean if I were preparing for the Zombie Apocalpyse there are better choices for canned food & bartering items.
Food would be...
Tuna, salmon, sardines, beans, peanut butter, coffee, sugar, rice, etc...Tell him to lay off the "tomato based" stuff. It does not store well long term.
You want high nutrition, high protein. Canned ravioli is very processed and not very nutritious from a "health" standpoint.
Bartering items would be cigarettes, liquor, and bullets. Then you have the medication & first aid category.
Also innoculations...My dd had to get an Typhoid innoculation for China. So does not take a leap to figure out you need up to date on immunizations (include Hepatitis in there) and in addition you can go get innoculations for Typhoid, Rabies, and a whole host of things. That would be something I would do. Think about it. If the "end of the world" happens disease will spread. Typhoid is from living in less that clean conditions.
Of course the most important item would be clean water. That is our limiting factor for life, right now.
Anyway, at least have a talk with him. At the very least he is having anxiety over this. Maybe you can talk with him and redirect some things.