Oxygensaturated

Oxygen-saturated is a descriptive term for a state in which a system contains the maximum amount of oxygen that can be dissolved or bound under the prevailing conditions. The phrase is used in chemistry, environmental science, physiology, and medicine to indicate a level at equilibrium with an oxygen source, as opposed to undersaturated states.

In liquids, dissolved oxygen is governed by Henry's law. The saturation concentration depends on temperature, pressure, and salinity. As temperature rises, the solubility of oxygen generally decreases, while higher partial pressure of oxygen or increased aeration raises the dissolved amount toward saturation. For example, freshwater at about 25°C under atmospheric pressure is typically air-saturated to roughly 8–9 mg/L, while near 0°C it can approach 12–14 mg/L. In saline waters, concentrations are lower. Oxygen-saturated liquids are analyzed by measuring dissolved oxygen or estimating from gas-phase conditions.

In biology and medicine, oxygen saturation often refers to the fraction of hemoglobin binding sites occupied by oxygen, expressed as a percentage. Normal arterial oxygen saturation is about 95–100%. Venous saturation is lower and varies with metabolic activity. Clinically, saturation is assessed with pulse oximetry or arterial blood gas analysis, guiding supplemental oxygen therapy and other interventions.

Applications include maintaining oxygen-saturated water in aquaculture and wastewater treatment to support aerobic processes, controlling oxygen levels in fermentation, and ensuring appropriate atmospheres in food packaging. Caution is warranted, as excessive oxygen exposure at high pressures can cause oxygen toxicity and oxidative stress in biological tissues.