Right, but the point is, that number is so small as to basically be fake. We're talking 1% the weight of a human cell. These kinds of instruments are extremely sensitive, and will ping off of nothing, or noise. Even then - its hard to trust whats actually being detected is fentanyl. A lot of analytical tests simply arent that specific.

It's not that theres some contamination - its that this detection process only pings under extremely specific circumstances that aren't actually happening.