Really   It claims halfway though the article that    In the military ShelterinPlace is comparable to buttoning up and has proved life saving in many instances Which instances exactly Was there a chemical or biological attack in some war recently I hadnt heard about it Which exact war was it and when was the chemical attack made Because unless there actually was a chemical or biological attack the only time SIP could have been used is either during training or during false alarms In either case it could not have actually saved any lives so I am dubious about this claim  I also notice that above this it says among other things   If the occupants breathingproduced carbon dioxide is the only consumer of oxygen in the room then carbon dioxide levels would not begin to reach dangerous values until  hours had passed in all likely  family home scenarios Carbon dioxide does not consume oxygen to the the best of my knowledge and are  family homes really an good example home to use Around here its usually one family per home although that may not be the case in other places Or perhaps you mean  person family That would be a bit closer to the average