Quick version...
Should you use it on bee frames - this would not be allowed.
Is it safe to use on frames - most likely.
Long version...
I assume Dipel would have been licensed as a "Crop protection product", therefore using it for any other reason would be outside its scope of use.
Since the neonicotinoid debacle, the regulators are extra paranoid about bees. They are demanding additional bee tests on many new products. And making the manufactures of many existing products complete bee testing ready for when their product/s come up for re-certification.
Bee testing has become very expensive due to increased demand. And the limited capacity for testing is causing delays on the certification of some products.
If the manufactures of Dipel were to get their product certified for use on bee frames, then it would most likely be time consuming and very expensive. And give them additional headaches for years to come each time it needs re-certification.
The treatment of frames is an odd one in terms of its classification. Its clearly not a veterinary medicine or Crop protection product. So I don't know how the regulators would view it.
Dipel has probably undergone some bee testing, most likely definitive exposure testing. I suspect at least some elements of the authorities and definitely the manufactures are aware what bee keepers are doing with dipel. So think, if there was an indication it may be harmful to bees or dangerous to use in this way, then the authorities would warn agents such use.
I looked at the technical info for B401 and B402, the only notable difference was B402 will have an extended shelf life. So I am guessing this is why they are changing it.
I contacted an Italian ebay seller who sold a lot of Dipel last year. He told me he currently cannot get any because of disruptions in the supply chain due to covid, he was unsure when he will have any more.
Yep, I think the tub is two lifetimes worth.
