HAZARD PREVENTION Three methods are used to control the impact of hazards. The first, and preferred, is to prevent the hazard at  the  design  stage.  The  second  is  to  identify  and eliminate  existing  hazards.  The  third  is  to  reduce  the likelihood and severity of mishaps from hazards that cannot  be  eliminated. Hazards may be prevented through appropriate actions  during  the  design  process,  when  operating procedures  are  developed,  and  when  equipment  is purchased.   The   hazard   would   never   exist   if   we anticipated problems and eliminated them before they reached  the  worker.  Systems  commands  are  responsible for preventive actions such as system safety reviews, design  reviews,  and  the  development  of  operating  and purchasing  procedures  designed  to  eliminate  hazards. Usually,  ships  and  shore  commands  have  little control  over  the  design  process.  If  the  design  of equipment  currently  in  use  is  hazardous,  retrofitting  or redesign  may  be  required.  If  redesigning  the  equipment is beyond the scope of the activity, it may request help from the systems command or higher authority. The activity can then use that redesign information for future designs and purchases. Hazards in the workplace may arise as the result of an inadequate preventive maintenance program. An effective preventive maintenance program can keep equipment and material from degrading to the point that they  become  an  operational  hazard. Standard operating procedures (SOPs), instruc- tions, or similar directives that tell how to perform work can prevent hazards from occurring. Obvious examples include  SOPs  for  tank  cleaning,  foul  weather  operations, and asbestos removal. Personnel must be familiar with appropriate SOPs and current updates applicable to their duties. Many  hazards  may  be  prevented  by  including appropriate   specifications   in   purchase   orders   for equipment/material.   Normally,   buyers   have   little control  over  specifications  for  equipnlent/material purchased through the Navy supply system. However, since  a  considerable  amount  of  material/equipment  is locally  purchased,  you  can  prevent  hazards  by purchasing  the  proper  types  of  material  in  the  proper amounts. Hazardous material is of special concern. We must minimize  all  local  purchases  of  potentially  hazardous material.  Afloat  commands  should  purchase  only material  listed  on  the  Shipboard  Hazardous  Material List  (SHML).  Shore  commands  should  purchase  only material listed on the Authorized Use List (AUL). HAZARD CONTROL When  preventing  hazards  is  impossible,  we  must control their effects by reducing the severity of the hazards. We use several methods to control hazard possibilities. The preferred order in which we use them is (1) substitution, (2) engineering controls, (3) admin- istrative controls, and (4) use of personal protective equipment. Substitution Replacing   an   existing   process,   material,   or equipment with a similar item having a lower hazard potential may reduce risks of injury or illness. Be careful in substituting materials by making sure they are made of technically acceptable materials that will not create a new   hazard.   Contact   NAVSEA/NAVAIR   for substitution  approval.  Naval  Supply  Systems  Command (NAVSUP)   must   approve   hazardous   material substitutions. Engineering Controls Engineering  controls  used  to  control  hazards include isolation and ventilation. ISOLATION.—  Isolation is the physical separation of people from contact with a hazard. This method involves the use of a barrier or limiter. It may be in the form of a physical barrier or involve separation by time or   distance.   Examples   include   machine   guards, electrical  insulation,  sound  barriers,  and  remote- controlled equipment. VENTILATION.—  Ventilation is the control of potentially hazardous airborne substances through the movement of air. Two methods are  general  ventilation (or  dilution  ventilation)  and  local  exhaust  ventilation. General  ventilation  is  the  dilution  of  an  airborne substance   by   mixing   it   with   the   surrounding uncontaminated  air.  Local  exhaust  ventilation  (fig.  3-1) is the removal of an airborne substance at its source or point of generation. This method of ventilation prevents the  airborne  contaminants  from  passing  through  the worker’s  breathing  zone.  Local  exhaust  ventilation  is the preferred and more economical method. The use of general  ventilation  should  be  limited  to  the  control  of heat, humidity, or low toxicity solvent vapors when no other  ventilation  is  possible. 3-6