What percent purity must oxygen produced by physical separation have?

Oxygen produced by physical separation processes, such as cryogenic distillation or membrane separation, must meet a minimum purity of at least 90%. This is because medical-grade oxygen must be sufficiently pure to ensure safety and efficacy when administered to patients. A purity level of 90% is considered the minimum to ensure that the oxygen provided is free from significant impurities that could adversely affect patient health, especially in clinical settings where oxygen therapy is a standard treatment for various conditions. Purification methods are designed to achieve this level, enabling compliance with regulatory standards for medical gases. Lower purity levels could lead to harmful effects or reduced effectiveness in therapeutic applications.