The tests were conducted by two independent testing laboratories on behalf of the National Institute of Justice Technology Assessment Program Advisory Council Protective Equipment Committee. The mechanical tests were conducted under four environmental conditions: (1) ambient, (2) low temperature (14 degrees F.), (3) high temperature (122 degrees F.), and (4) following immersion in water at ambient temperature. In addition, proper product labeling, peripheral vision (field of unobstructed view to the side of the helmets), and inside/outside projections were determined. Face shields were subjected to mechanical testing to determine impact protection and retention characteristics, and optical tests were conducted to determine the parameters of light transmission, distortion, and the refractive/resolving power. None of the 27 models of helmets tested complied with the labeling requirements; however, one riot helmet and eight crash helmets complied with all physical performance requirements under all environmental conditions. Only one face shield complied with all performance requirements, but it was attached to a helmet that did not meet requirements. Overall test results are summarized in tabular form. (Author summary modified)