Book excerpt: The report is a complete compilation of the papers presented and the Proceedings of the 3rd Annual Conference on Atmospheric Contamination in Confined Spaces, sponsored by the Aerospace Medical Research Laboratories and held in Dayton, Ohio on 9, 10, and 11 May 1967. Major technical areas discussed by the invited speakers, members of the Open Forum and Conference attendees included toxicological evaluation of atmospheres and contaminants, histopathological evidences of toxicity, evaluation of cabin materials, instruments and detection techniques, measurement of behavioral responses, and life support systems. Included as an Appendix, but not presented at the Conference, is a status report on oxygen toxicity prepared by Dr. Harold Kaplan.