I work for a company that recycles once fires brass. The small primers in the .45 ACP brass are used in all Non-Toxic rounds. From what I have been able to assertain, the most toxic part of any round being discharged is the residue from the primer. In order to comply with the Non-Toxic standards, a new explosive for primers had to be developed that was Non-Toxic. This was too hot for the large primers, hence the new small primers. Now the bullet, powder and primer are all Non-Toxic. We have to sort through all of our .45 ACP brass and segregate all of the small primers from the large, before we process it for sale.