Electromagnetic Radiation Hazards CBR PROTECTIVE EQUIPMENT Almost  everyone  is  constantly  subjected to nonionizing radiation in varying degrees. Nonionizing radiation is electromagnetic radiation restricted to the frequency spectrum commonly referred to as the radio-frequency (rf) region up to and including laser radiation (visible light). Common types of rf-producing equipment are radio transmitters, radars, microwave ovens, and gun and missile directors. The development of systems with high-power rf transmitters and high-gain antennas has increased the possibility of biological injury to personnel working in their vicinity. Presently, the  only  known  effects  of  overexposure  to  rf radiation are an increase in body temperature or a temperature rise in specific organs of the body. Nonthermal effects (such as sterility) are not certain at this time. The Naval Medical Command established safe limits for exposure to radiation in BUMEDINST 5470.13. Those limits are based on the power density of the radiation beam and the exposure time of the human body in a radiation field. The following precautions should be taken to ensure that personnel are not exposed to radiation that exceeds the established safe limits: • Keeping radar beams pointed away from personnel working areas • Observing warning signs that indicate the existence  of  rf  radiation  hazards  in  a specific location or area Another hazard of rf radiation is rf burns. An rf burn hazard exists if sufficient rf voltage is induced on a metallic object to cause pain, visible skin damage, or involuntary reflex action to a person who contacts the object. Any burn injury that occurs is the result of the heat produced by a current flow through the skin at the contacted area. The rf voltages on metallic objects can be induced by radiation from nearby transmitting antennas. Hazardous voltages have been  found  on  crane  hooks,  running  rigging, booms, antisubmarine rocket (ASROC) launchers, and parked aircraft. Attempts to reduce these hazards are being managed by the Naval Sea Systems  Command  (NAVSEA)  and  involve equipment design modifications. However, the most important deterrent is personnel training and awareness. Personnel  protective  equipment  used  in chemical warfare (CW) defense includes masks, clothing, decontaminating kits, and antidotes for certain chemical agents. Depending on your duty station and actual combat assignment, you may be  issued  certain  items  of  this  equipment. Knowing the correct procedures for the use of the equipment  is  vital.  The  following  paragraphs provide descriptions of these procedures, but only practice can assure that you follow them properly. Chemical, Biological, and Radiological Defense, Handbook for Training, S-5080-AA-HKB-010, and NSTM, chapter 470, list detailed procedures for the use and maintenance of CW protective equipment. CBR PROTECTIVE MASKS The protective mask is your personal first line of CBR defense since it protects vulnerable areas such as the eyes, face, and respiratory tract. The protective  mask  removes  airborne  radioactive material and biological warfare (BW)/chemical warfare (CW) agents from the air before they are inhaled. However, the mask does not provide protection against some common gases, such as carbon monoxide, carbon dioxide, tritium, and ammonia. It also does not protect against oxygen deficiency. If you must enter areas or compart- ments that have a deficiency of oxygen, the Navy’s oxygen breathing apparatus (OBA) must be used. The general operation of all types of protective masks is essentially the same. As the wearer inhales, air is drawn through a filtering system. This system consists of two filters: a mechanical filter,  which  clears  the  air  of  solid  or  liquid particles, and a chemical filter, usually activated charcoal, which absorbs or neutralizes toxic and irritant vapors. The purified air then passes to the region of the mask where it can be inhaled. Exhaled air is expelled from the mask through an outlet valve constructed to open only to permit exhaled air to escape. The useful life of any filter element depends on four conditions: (1) the type and concentration of the toxic agent or agents in the air, (2) the duration of exposure to the contaminated air, (3) the breathing rate of the wearer, and (4) the temperature and humidity. A change in any of these conditions may affect the useful life of a filter element; it can hold only a definite weight of a toxic agent under given circumstances. Minor 6-9