What is the maximum CO level in Grade D air?

In the context of Grade D air, which is primarily used for breathing in confined spaces and during activities involving potential exposure to hazardous environments, the maximum allowable carbon monoxide (CO) level is indeed set at 10 parts per million (ppm). This standard is established to ensure the safety and well-being of individuals who might be exposed to this gas, as CO is known for its toxic properties, even at low concentrations. Monitoring and strict adherence to these limits are critical because increased levels can pose serious health risks, leading to symptoms such as headaches, dizziness, and in severe cases, loss of consciousness or even death.

This definition of Grade D breathing air criteria is in line with OSHA (Occupational Safety and Health Administration) regulations, which prioritize maintaining a safe working environment in potentially hazardous settings. The established limits reflect a balance between safety and practicality, allowing workers to operate in necessary conditions without incurring health risks.