This year’s joint meeting with the Undersea and Hyperbaric Medical Society was held at the Hyatt Regency Hotel in Downtown Atlanta from June 1–6^th, 2025. On Saturday May 31^st, the annual meeting of the International Airline Medical Association (IAMA) was held. This year’s meeting was excellent! Actually, most of them are excellent.

A major portion of the morning was devoted to hearing physicians from the Centers for Disease Control and Prevention (CDC). This proved to be a great review for myself as I generally do not deal with their issues. The first speaker, Clive Brown, MBBS,

Ryder VE, Williams ES. Revisions to limits for propylene glycol in spacecraft air. Aerosp Med Hum Perform. 2022; 93(5):467–46.

DOI: https://www.doi.org/10.3357/AMHP.6037.2022

In the above article, in the second paragraph of the section on SMAC Development, the authors stated “Importantly, this value (32 ppm) for pure propylene glycol exceeds the saturated vapor concentration for most propylene glycol/ water mixtures being considered as thermal control fluids in exploration spacecraft.” This is inaccurate. The saturated vapor concentration for PG is 171 ppm at standard temperature and pressure, and the vapor pressure increases as water is added to the mixture.

The authors and