out  in  strict  compliance  with  procedures established to assure safety of flight and mission completion. This  section  establishes  procedures  and  re- quirements  for  the  quality  control  of  gaseous oxygen  that  is  stored,  transferred,  and  used  for breathing  purposes  by  aircrews.  This  section  is applicable  to  all  personnel  who  are  responsible  for supervising   or   performing   the   operations   as- sociated  with  and  servicing  of  the  aircraft  with aviators  breathing  oxygen. Quality  Control  Requirements  of Gaseous  Oxygen The  procurement  limits  for  purity  and  con- tamination,  which  include  the  absence  of  odor, of aviators gaseous breathing oxygen must meet the  requirements  of  the  current  issue  of  MIL- O-27210. The on-station monitoring of aviators gaseous breathing oxygen for contamination is performed by  a  sniff  odor  test. WARNING The odor test is very hazardous due to the high pressure in the cylinder. Do not place your face or nose directly into the venting gas stream and do not take deep breaths. Discontinue “sniffing” any gas at the first indication of irritation of the nasal pas- sages or at any sign of physical discomfort. Some contaminants are extremely irritat- ing, poisonous, or toxic, and can cause physical injury. The odor test can only be performed safely if the procedures are followed exactly. NOTE Persons  temporarily  unable  to  detect  or classify  odors  because  of  head  colds,  hay fever,   etc.,   must  be  excluded  from  the assignment of inspecting for the presence of   odorous   contaminants. If  an  odor  is  detected,  discontinue  the inspection  process.  When  detected,  an  attempt should  be  made  to  classify  it,  such  as  “acrid,” “sweet,  ”  “rotten  egg,”  “glue  like,”  etc.,  as  this will help in the identification of the source of the contaminate. Gaseous Oxygen Servicing Trailer Gaseous   oxygen   servicing   carts   must   be sampled  and  tested  whenever  contamination  is suspected   or   after   the   completion   of   any maintenance  action  performed  on  the  cart.  An odor  test  must  be  conducted  prior  to  servicing  any aircraft system. This is accomplished by opening slightly  the  valve  at  the  terminal  end  of  the recharging hose and smelling the escaping gas in accordance with the procedures described in the A6-332AO-GYD-000.  If  an  odor  is  present,  the servicing  cart  will  not  be  used  to  service  the aircraft. Each cylinder must be inspected for the following: .  Proper  painting  and  marking. l Valves are tightly closed and not leaking. l  Safety  caps  and  safety  plugs  are  secure. .  Hydrostatic  test  date  is  current. .  All  valves,  manifold,  servicing  hose,  and cylinders are clean and free of grease and oil. The presence  of  any  grease  or  oil  on  the  valves  or cylinders  must  be  reported  to  the  maintenance officer  for  necessary  action,  and  the  servicing  cart must  be  placed  in  a  contaminated  status. HIGH-PRESSURE  AIR Using   high-pressure   compressed   air   safely requires  knowledge  and  skills.  Despite  all  the safety programs and posters regarding this shop hazard,  reports  of  fatalities  and  serious  injury from  this  cause  continue  to  accumulate. High-pressure  compressed  air  is  provided  from one  of  three  sources: 1.  A  portable  high-pressure  cylinder 2.  A  cascade-type  servicing  trailer  equipped with several cylinders 3.  Direct  service  from  a  portable  high-pressure air  compressor Each of these sources is no less dangerous than the  precautions  already  discussed  for  handling oxygen cylinders. Precautions apply generally as well for the handling and stowage of compressed air cylinders. Do not fill any cylinder with a gas other than that   gas   for   which   the   cylinder   has   been specifically  designated.  Explosive  mixtures  may 1-6