At this point it seems like it might be more effective to mandate the opposite: labels that indicate that the product is allergen free for X class of allergen.
That way the default (no label) = might contain allergens, and the presence of the label guarantees your safety.
Companies that take allergen cross contamination seriously can tout the label (and win the business of the allergic), companies that don't won't resort to purposefully including allergens in their product to avoid having to overhaul their cross contamination practices.
That way the default (no label) = might contain allergens, and the presence of the label guarantees your safety.
Companies that take allergen cross contamination seriously can tout the label (and win the business of the allergic), companies that don't won't resort to purposefully including allergens in their product to avoid having to overhaul their cross contamination practices.