some of the radar hazards you may encounter inside the ship. CATHODE-RAY TUBES (CRTs) Cathode-ray   tubes   can   be   very   dangerous   and should always be handled with extreme caution. The glass envelope encloses a high vacuum, and because of its large surface area, is subject to considerable force by   atmospheric   pressure.   (The   total   force   on   the surface of a 10-inch CRT is 3,750 pounds or nearly 2 tons; over 1,000 pounds is exerted on its face alone.) Proper  handling  and  disposal  instructions  for  a  CRT are as follows:    Avoid scratching or striking the surface.    Do not use excessive force when you remove or replace  the  CRT  in  its  deflection  yoke  or  its socket.    Do  not  try  to  remove  an  electromagnetic  CRT from its yoke until you have discharged the high voltage from the anode connector (hole).    Never hold a CRT by its neck.    When you set a CRT down, always place its face down on a thick piece of felt, rubber, or smooth cloth.    Always handle the CRT gently. Rough handling or a sharp blow on the service bench can displace the  electrodes  within  the  tube,  causing  faulty operation.    Wear  safety  glasses  and  gloves  whenever  you handle a CRT. RADIOACTIVE ELECTRON TUBES Electron tubes containing radioactive material are common to radar equipment. These tubes are known as Transmit-Receive  (TR),  antitransmit-receive  (ATR), spark-gap,   voltage-regulator,   gas-switching,   and cold-cathode gas-rectifier tubes. Some of these tubes contain   radioactive   material   that   has   a   dangerous intensity level. Such tubes are so marked according to military   specifications.   In   addition,   all   equipment containing   radioactive   tubes   must   have   a   standard warning label attached where maintenance personnel can see it as they enter the equipment. As long as these electron tubes remain intact and are not broken, no great hazard exists. However, if they are  broken,  the  radioactive  material  may  become  a potential hazard. The radioactivity in a normal collection of electron tubes   in   a   maintenance   shop   does   not   approach   a dangerous   level,   and   the   hazards   of   injury   from exposure are slight. However, at major supply points, the storage of large quantities of radioactive electron tubes in a relatively small area may create a hazard. If you   work   in   an   area   where   a   large   quantity   of radioactive   tubes   is   stored,   you   should   become thoroughly familiar with the safety practices contained in   Radiation  Health     Protection  Manual,  NAVMED P-5055.   By   complying   strictly   with   the   prescribed safety precautions and procedures of this manual, you should be able to avoid accidents and maintain a work environment that is conducive to good health. The   hazardous   materials   information   system (HMIS) contains a listing of radioactive tubes, along with   proper   stowage   techniques   and   disposal procedures.    Afloat   Supply   Procedures,   NAVSUP P-485  contains  detailed  custody  procedures.  Be  sure you use proper procedures whenever you dispose of a radioactive tube. Also, be aware that federal and state disposal regulations may vary. Any  time  you  handle  radioactive  electron  tubes, take the following precautions: 1.   Do not remove a radioactive tube from its carton until just before you actually install it. 2.   When   you   remove   a   tube   containing   a radioactive material from equipment, place it in an appropriate carton to keep it from breaking. 3.   Never carry a radioactive tube in your pocket, or elsewhere  on  your  person,  in  such  a  way  that could cause the tube to break. 4.   If  you  do  break  a  radioactive  tube,  notify  the appropriate authority and obtain the services of qualified   radiological   personnel   immediately. The basic procedures for cleaning the area are covered in the EIMB, General, Section 3. If you are authorized to clean the area, get a radioactive spill kit with all the materials to clean the area quickly and properly. The ship must have at least one   radioactive   spill   disposal   kit   for   its electronic spaces. It may have more, depending on the number and location of spaces in which radioactive  tubes  are  used  or  stored.  Each  kit should contain the following items: Container—Must be large enough to hold all cleanup   materials   and   pieces   of   broken 3-15