TM 10-6640-215-13 1-8.  SAFETY, CARE, AND HANDLING- continued. a.   General Precautions.  The following are general safety precautions that need to be observed by all operators of the Petroleum Laboratory. Always  be  mindful  of  tests  in  progress.    Never  allow  horseplay  or  loud  talking  that  would  divert  the  attention  of laboratory technicians.  If it is necessary to leave the laboratory or to leave a test in progress, make certain no safety hazard will result from your absence. Do not attempt to perform tests simultaneously unless each test can be given the required attention. Whenever in doubt concerning any operation, consult qualified authority for advice. Do  not  attempt  unauthorized  shortcuts  to  save  time,  as  they  generally  are  not  in  accordance  with  safe  laboratory procedures. Be  prepared  for  any  emergencies  which  may  arise,  and  be  familiar  with  the  proper  action  to  take  in  event  of emergencies. When ending daily operations, make a thorough and orderly check of laboratory, equipment and facilities to ensure that no hazards may develop during the time the laboratory is unattended. b.  Preventing Fires.  The following fire prevention rules must be observed in all laboratory procedures: Do not smoke in the Petroleum Laboratory. Never leave open flames or heating elements unattended. Never pour hot liquids into drains.  Set aside hot liquids to cool thoroughly in covered containers before discarding. Make sure that chemicals which may react to produce dangerous fumes, fires, or explosion are stored in their proper places. Make  sure  that  volatile  liquids  and  flammable  products  are  kept  away  from  heat  sources,  open  flames,  direct sunlight, and electrical switches. Make certain that there is no open flame or exposed heating element nearby when pouring highly volatile liquids. Clean up chemical and liquid spills immediately. Always pour acid into water; never pour water into acid. Keep oily rags in a metal, airtight, closed container.  Do not store oily rags in cabinets or drawers. Make certain laboratory is adequately ventilated. 1-3