Blood is extremely dangerous when carried to the blood via the lungs by inhalation, because carbon monoxide irreversibly binds to hemoglobin to form carboxyhemoglobin, so that less hemoglobin is free to bind oxygen, and fewer oxygen molecules can be transported throughout the blood. This can cause suffocation insidiously. A fire burning in an enclosed room with poor ventilation presents a very dangerous hazard, since it can create a build-up of carbon monoxide in the air. Some carbon monoxide binds to hemoglobin when smoking tobacco. Blood for transfusion is obtained from human donors by blood donation and stored in a blood bank.
Blood doping used by cyclists in combination with cobalt chloride/desferrioxamine stimulate and de-regulate the natural production of erythropoietin hormone. At physiologically low PaO around 40 mmHg, EPO is released from the kidneys to increase hemoglobin transportation. The combination of drugs consistently releases EPO due to increased transcription at the cellular level. The effect wears off when the HIF stabilizers, cobalt chloride/desferrioxamine is excreted and/or decayed by the body. Myo-inositol trispyrophosphate (ITPP), also known as compound number OXY111A, is an allosteric effector of hemoglobin which causes a rightward shift in the oxygen–hemoglobin dissociation curve, increasing the amount of oxygen released from red blood