Wow. I was just looking at rust inhibitor msds sheets. I didn't come away with anything except a headache!
Grilling24x7- Dont sweat it. From what i can gather, the rust inhibitor is a normal step during manufacturing process. Looks like all barrels get it. Personally I'd take it apart and burn it out. Just remember if you ever want to take the paint off a lid, use a angle grinder with wire wheels and/or cup brushes. The heat from a fire or torch will warp the lid.
Plus burning is free vs paying to have it sandblasted. Some businesses will give you their old and broken pallets. 2 or 3 is plenty.
UDS, mini wsm, 22.5" weber kettle