Let me get this straight. You can’t buy the medicine called Sudafed, but you can buy bomb making ingredients without limit?
Now you're catching on. Isn't this a great system. Oy!
Ammonium nitrate comes in two grades, fertilizer and dynamite. Both are capable of creating mass explosions.
The 1947 Texas City Explosion was caused when the SS Grandcamp, carrying a full load of fertilizer exploded.
It's almost impossible to regulate chemicals so that someone cannot make an improvised WMD. Just grab ammonia and bleach and you have mustard gas. Mix swimming pool chlorine and brake fluid will create a fire bomb and you can create free chlorine gas just by dumping a quart of water into a five gallon bucket of granulated swimming pool chlorine.