1.1 ,This guide covers a method for the measurement of the relative extent of oxidation present in HDPE homopolymers and ultra-high-molecular-weight polyethylene (UHMWPE) intended for use in medical implants. The material is analyzed by infrared spectroscopy. The intensity (area) of the carbonyl absorptions (>,C=O) centered near 1720 cm^-1 is related to the amount of chemically bound oxygen present in the material. Other forms of chemically bound oxygen (C-O-C, C-O-O-C, C-O-H, and so forth) are not captured by this guide.