In a high concentration oxygen pure environment, the rate or speed of combustion is significantly faster compared to low air. This is because oxygen acts as a fuel and supports combustion. When there is a higher concentration of oxygen, there are more oxygen molecules available to react with the fuel, resulting in a more rapid and intense combustion process.

In contrast, in low air, the concentration of oxygen is lower, which limits the amount of oxygen available for combustion. This can result in a slower and less efficient combustion process. The difference in combustion rate between high concentration oxygen pure and low air is particularly noticeable in controlled environments such as laboratories or industrial settings where precise control over combustion is required.