As a subject matter expert in respiratory health, I can tell you that the safe oxygen level for humans is crucial for maintaining proper bodily functions. The human body has a narrow range for what is considered a normal and healthy oxygen level in the blood. Normal arterial blood oxygen levels, as measured by the percentage of oxygen in the blood (known as the oxygen saturation level), are typically between 95% and 100%. This is often represented as 95-100% SpO2 when measured by a pulse oximeter, which is a non-invasive device that clips onto the finger. When the level falls below 90%, it is generally considered low, which can lead to a condition known as hypoxemia. Hypoxemia means there is not enough oxygen reaching the body's tissues, which can be dangerous if not addressed promptly. It's important to note that while 95-100% is the normal range, slight variations can occur in healthy individuals, especially with changes in altitude, physical activity, or certain health conditions. However, consistently low oxygen levels can be a sign of a health issue and should be evaluated by a healthcare professional. read more >>

The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal blood oxygen levels in humans are considered 95-100 percent. If the level is below 90 percent, it is considered low resulting in hypoxemia.read more >>