If he means real explosives like RDX, PETN, and a box of flaked TNT, there is already a background check and license system in place through ATFE, the Federal Explosives License, which has several types and subtypes depending on what you are doing.
If he means to include PROPELLANT powders which by design do not “explode” then I have a problem.
He needs to rush this through before we find out the bad guys used match heads and sugar, or Stump Remover and sugar.
U.S. Senator Frank Lautenberg (D-NJ) announcing not one, but two "gunpowder control" amendments to the not-quite-dead-yet S. 649. S. Amd. 736, the "Explosive Materials Background Check Act," and S. Amd. 737, of the same title, appear to be essentially the same, with 737 apparently making some technical refinements to 736. A stand-alone bill is apparently also coming.
Basically, the legislation appears to impose the same background check requirements for the purchase of any amount of black powder or smokeless powder that are now imposed on the purchase of firearms, including, of course, the (in?)famous "Lautenberg Amendment," which retroactively bans purchases for misdemeanor domestic violence convictions.