possible for a person to squeeze the reel flanges during handling even though a tape strap is properly in place, as shown in figure 2-9. Handling tapes in this manner will certainly   result   in   tape-edge   damage.   In   addition, defective  or  improper  size  straps  may  deflect  (twist  or warp)   the   reel   flanges,   causing   tape-edge   damage. Nonetheless,  when  handled  with  care,  the  wrap-around tape strap can bean effective method of tape protection. Anytime you are handling magnetic tape, regardless of how it is protected (by a canister or a tape strap),   always   use   good   judgment   and   follow   the applicable safeguards, as follows: When a tape is not actually being used, keep it in  its  protective  container  to  avoid  accidental breakage and unnecessary contamination. Do  NOT  leave  empty  tape  canisters  open  as this    allows    entry    of    dust    or    other    tape contaminating matter. Hang wrap-around straps in a clean area while the tape is in use. Whenever  you  return  a  tape  to  its  respective canister, you must ensure that a clean stopper is used. NOTE: A stopper is a one-inch piece of foam rubber  the  same  width  as  the  reel  (inside  the flanges)  and  one-half-inch  thick.  Stoppers  are used  to  keep  the  tape  from  unraveling  once inside the canister. Figure 2-9.—Magnetic tape being held improperly- the fingers should go through the hub hole without squeezing the flanges. Never use rubber stoppers with wrap-around straps. The  extra  thickness  could  result  in  the  tape  being embossed (leaving a permanent imprint). While working with tapes in canisters, canisters may be stacked for short periods of time. NOTE:  Avoid   stacking   more   than   10   canisters, since weight can cause the canisters on the bottom to crack. Avoid stacking tapes with wrap-around tape straps, because doing so can cause tape-edge damage. Store magnetic tapes in a vertical position. Always  handle  tape  reels  by  the  center  hub,  never by the flanges. NOTE: If you happen to drop a tape reel, check it immediately for cracked flanges and the tape  itself for possible edge damage. Periodically remove and check inside the flange and hub  areas  of  take-up  reels  on  tape  cleaning  and certifying equipment for dirt or other contamination. Also check these reels (at the hub) periodically for signs  of  warpage  or  cracks.  Periodically  check  the mounting hubs on your equipment to ensure they are tight  (secure).  This  prevents  a  reel  of  tape  from wobbling during a cleaning or certifying operation. When you mount a tape on a device, always push in on the hub itself, never on the outer flanges. Never touch or handle the recording surface of  the tape. Never  place  magnetic  tape  on  top  of  equipment because of the heat generated by the equipment and because  internal  magnetic  fields  within  the  device may  scramble  recorded  bits  of  information  on  the tape. Smoking  should  not  be  allowed  in  working  spaces where   magnetic   tape   is   being   used.   Smoking   is never   permitted   while   handling   magnetic   tape, attending  to  tape  units,  or  working  in  the  library area.  Ashes  may  contaminate  tapes,  and  live  ashes may   cause   permanent   damage   if   they   come   in contact with the tape. 2-15