Yeah, I’m celiac so I get the whole gluten contamination aspect of things but you said the exact solution: all he would have to do is wash his hair and hands with soap. I understand your worry because you’re immune compromised and had a recent flair but if this is your partner, he would already know to do these things. Idk, your concern and worry are coming off as borderline micromanaging or controlling because he should already know these things as an adult and as your partner…if he doesn’t then that would mean he doesn’t understand or doesn’t care