Schlüggell
I have no experience with Picloram...but 2,4-D on its own was banned in the early 70s.
However, it is still used due to a technical issue with Chemical testing...
When you mix 2 banned substances together, the 'new' soup is considered a different substance in the eyes of the law that needs to be tested on its own...In theory the 2,4-D is a salt of the 'true' chemical {but try to prove it...} thus further considered 'safe'.
Soopo, when banned in 70s; 2,4-D & 2,4,5-T were banned for use by themselves - but later in the 80s when mixed together it was considered 'safe'.
'Picloram' - 2-Pyridinecarboxylic acid , CAS Number: 2545-60-0
4-Amino-3,5,6-Trichloro-Monopotassium Salt
'2,4-D' - 2,4-Dichlorophenoxyacetic acid , CAS Number: 94-75-7
'2,4,5-T' - 2,4,5-Trichlorophenoxyacetic acid , CAS Number: 93-76-5