We have just received some frangible ammo in 9mm, 40 S&W, 45 ACP and 223 Rem. It's made by ICC, a quality manufacturer which sells primarily to law enforcement.
Frangible ammunition is no different than normal target ammo except the bullet. Instead of a lead core with a copper jacket, frangible bullets are made from compressed copper powder or polymer. Whenever the bullet strikes something harder than itself at full speed, it crumbles to pieces. Still dangerous if you’re standing on the wrong side of the muzzle, but once they hit a hard target, the bullet fragments are too small to cause any harm from ricochets.
As such, frangible rounds reduce lead exposure by having both a non-lead primer and projectile, so it’s 100% lead free. It allows shooters to train closer on steel, reducing muzzle recoil and maximizing range efficiency (never replace steel targets).