Highest equivalent altitude exposure survived

On 14 December 1966, Jim LeBlanc (USA) was a NASA volunteer test subject who was testing space suits inside a depressurisation chamber in Houston, Texas, USA. When an equipment failure disconnected the hose which kept his space suit pressurised, he was instantly exposed to a partial vacuum equivalent to an altitude of 120,000 ft (36,576 m), with a pressure of just 0.1 psi. It took 87 seconds for the chamber to be repressurised to 14,000 ft equivalent altitude, at which point LeBlanc regained consciousness.

He recalled the sensation of feeling his own saliva boiling off his tongue just before he passed out. He suffered no long-term effects.