Explain the poisonous nature of carbon monoxide.

1. Carbon monoxide is highly poisonous gas. Air containing 0.5% carbon monoxide by volume if inhaled could result in death.
2. Carbon monoxide combines with haemoglobin present in RBCs of our body to form a stable compound carboxyhaemoglobin.
3. This stable compound does not allow haemoglobin to absorb or carry oxygen, thus our body cells gets deprived of oxygen. This causes paralysis of respiratory organs and results in death due to suffocation.