 It is possible to safely breathe dense gases such as xenon or sulfur hexafluoride when they are in a mixture of at least 20 % oxygen . Xenon at 80 % concentration along with 20 % oxygen rapidly produces the unconsciousness of general anesthesia ( and has been used for this , as discussed above ) . Breathing mixes gases of different densities very effectively and rapidly so that heavier gases are purged along with the oxygen , and do not accumulate at the bottom of the lungs . There is , however , a danger associated with any heavy gas in large quantities : it may sit invisibly in a container , and if a person enters a container filled with an odorless , colorless gas , they may find themselves breathing it unknowingly . Xenon is rarely used in large enough quantities for this to be a concern , though the potential for danger exists any time a tank or container of xenon is kept in an unventilated space . 
 It <a href='drop_aux' title='1'><mark>is</mark></a>possible to safely breathe dense gases such as xenon or sulfur hexafluoride when they <a href='drop_aux' title='2'><mark>are</mark></a>in a mixture of at least 20 % oxygen . Xenon at 80 % concentration along with 20 % oxygen rapidly <a href='uninflect' title='3'><mark>produces</mark></a> the unconsciousness of general anesthesia ( and <a href='been_done' title='4'><mark>has</mark></a> been used for this , as discussed above ) . Breathing <a href='uninflect' title='5'><mark>mixes</mark></a> gases of different densities very effectively and rapidly so that heavier gases are purged along with the oxygen , and do not accumulate at <a href='None' title='6'><mark>the</mark></a><a href='negative_concord' title='7'><mark>bottom</mark></a> of the lungs . <a href='dey_it' title='8'><mark>There</mark></a> is , however , a danger associated with any heavy gas in large quantities : it may sit invisibly in a container , and if a person <a href='uninflect' title='9'><mark>enters</mark></a> a container filled with an odorless , colorless gas , they may find themselves breathing it unknowingly . Xenon is rarely used in large enough quantities for this to be a concern , though the potential for danger <a href='uninflect' title='10'><mark>exists</mark></a> any time a tank or container of xenon is kept in an unventilated space . 
It possible to safely breathe dense gases such as xenon or sulfur hexafluoride when they in a mixture of at least 20 % oxygen . Xenon at 80 % concentration along witt 20 % oxygen rapidly produce the unconsciousness of general anesthesia ( and done been used for dis , as discussed above ) . Breathing mix gases of different densities very effectively and rapidly so dat heavier gases r purged along with da oxygen , and do not accumulate at no bottom of tdalungs . It is , however , a danger associated with any heavy gas in large quantities : it may sit invisibly in a container , and if a person enter a container filled with an odorless , colorless gas , they may find themselves breathing it unknowingly . Xenon is rarely used in bigass enough quantities for tdisto be a concern , though the potential fa danger exist any time a tank or container of xenon is kept in an unventilated space .