I can speak from personal history with it.
This past year we shipped a load of honey out—I believe we are a leader in the food safety area in our industry—and the honey being tested came back saying we had high levels of lead in the honey. We have samples of every lot and we keep track of everything, but we couldn't figure out where this lead was coming from. All we did was go back to our sample jars and send samples off to the same lab; the results came back as containing no lead. At the processor's plant, the samples had been mixed up.
If it hadn't been for the traceability, we would never have known this. What do you do then? You are labelled as having a lead problem or a chemical problem in your product; what do we do? It's condemned, but then we have evidence on our farm that says no, this is exactly what we have, and here's proof that this is what there is. If it's voluntary, you don't have that.
A lot of guys won't do it. I'm sure every industry is the same, but ours is exceptionally bad for it. Three years ago, the Alberta government did a honey sampling initiative. Every producer who wanted to take part—it was voluntary—sent samples to be tested. Any results that were found went back just to you. If there was problem, it went to the provincial apiculturalist's office, and he went to that producer and worked with him to find out what had caused the problem.