The Belvoir Research, Development and Engineering Center (BRDEC) was requested by the USAF to assist in evaluating the effectiveness of commercially offered used antifreeze recycling systems. BRDEC was solicited for assistance because of its mission responsibility for military antifreeze and because it is the preparing activity for antifreeze under MIL-A-46153. This report evaluates three commercial recycling systems using antifreeze samples collected and processed at both Tyndall AFB, FL, and McConnell AFB, KS. Seven sets of samples (each comprised of a recycled and the original used) were evaluated. A total of 11 laboratory were conducted on the samples. Coolant recycling, MIL-A-46153 antifreeze, Used coolant.