The author draws on his 30 years in oxygen safety and participation in the organizing task group of ASTM Committee G-4 on Compatibility and Sensitivity of Materials in Oxygen-Enriched Atmospheres and G-4 activities to review key industry and G-4 past actions relating to the selection of materials for oxygen and oxygen-enriched service. The Compressed Gas Manufacturers Association formed an Oxygen Regulator Research Committee in 1921. Sixty years later, the ASTM Guide for Evaluating Materials for Oxygen Service (G 63), the industry's first such guide, was published. Committee G-4 formation, membership, scope, and accomplishments to date, including test procedures, are reviewed. Tests currently used by several organizations are included. Future plans of Committee G-4 and its subcommittees are outlined. The standardization of test methods and guidelines for selecting materials will improve oxygen safety and benefit large and small organizations. Furthermore, it is anticipated that these ASTM standards will gradually be included by reference in future government regulations and association standards relating to oxygen safety.