What is the maximum allowable concentration of carbon monoxide in medical air?

The maximum allowable concentration of carbon monoxide in medical air is set at 25 parts per million (ppm). This limit is established to ensure patient safety, as carbon monoxide is a toxic gas that can lead to serious health complications, including hypoxia and carbon monoxide poisoning, especially in vulnerable populations such as those in healthcare settings.

Setting the limit at 25 ppm reflects a balance between ensuring the medical air is free from harmful levels of contaminants and the practical aspects of maintaining equipment and facility environments. Regulations and guidelines, such as those provided by the National Fire Protection Association (NFPA) and the Compressed Gas Association (CGA), help establish this standard to promote safe practices in medical gas systems. It is essential for medical facilities to monitor and maintain air quality to foster a safe healing environment for patients.

The lower concentrations proposed in the other choices do not reflect the established safety limits for medical air, making them less relevant in this context.