Is there any evidence regarding the risks of allergen cross-contamination in a typical residential kitchen environment?
Specifically, I'm wondering about situations like:
1) If a seasoned cast-iron skillet comes into contact with an allergen (e.g. gluten, soy), does a risk of cross-contamination still exist after washing/rinsing it? (it seems like it would be unavoidable that some residue gets incorporated into the pan's seasoning layer?)
2) A typical dishwasher may only use a few gallons of water and only perform 2 rinses in a cycle. Is it possible that some low concentration of allergen get "distributed" onto all the dishes and remains after the cycle is complete?
3) For non-porous surfaces (stainless steel, plastic cutting boards), is there any risk of allergens still being present after soap/water cleaning?
4) What about for porous surfaces (wooden cutting boards, wooden stir spoons)?
Ultimately, I'm trying to decide if a food allergy requires that my kitchen be completely devoid of the allergens (or anything that has ever come into contact with them), or if methods like soap+water washing are known to be sufficient to reduce allergen concentration to a safe level.