One other major cause to consider when there is an Oxygen deficiency is increased carbon dioxide production and carbon monoxide production. A high production rate of these gases, due to the lack of proper oxygen levels, can be dangerous. The surroundings become potentially unsafe when constant fluctuation in the minimum range is required. To avoid such potential harm to nature and your surroundings, you must maintain the minimum permissible Oxygen reading and check your flue gas analyser to see if it gives accurate readings.