This is a great idea! It could also expand to testing non-food items for dangerous chemicals (lead, heavy metals, etc). Many products keep a certification on-hand confirming that the product has been tested and found not to exceed the threshold, but I always am suspicious of (1) how thorough the initial testing actually is and (2) how well these results hold up as manufacturing continues. I realize I'm just plugging my pet-peeve though, not sure if others are as concerned about this.