ii
SAFETY
ii
ELECTRIC AND MAGNETIC FIELDS may be dangerous
2.a. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding current creates EMF fields around welding cables and welding machines
2.b. EMF fields may interfere with some pacemakers, and welders having a pacemaker should consult their physician before welding.
2.c. Exposure to EMF fields in welding may have other health effects which are now not known.
2.d. All welders should follow safe practices that minimize their exposure to electric and magnetic fields (EMF).
2.e. For welders wearing implanted pacemakers, safe welding practices are particularly important and additional procedures should be followed by those who have decided to continue to weld. (Hopefully in keeping with a doctor’s advice).
2.f. The following procedures will not eliminate exposure to EMF or the possibility of arc welding having an effect on a pacemaker, however if followed, they will significantly reduce exposure to electric and magnetic fields. Electric and magnetic fields are created any time electric current flows through a conductor, however it is not clear whether such exposure affects ones health.
2.g. Some researchers have reported that exposure to EMF may cause leukemia or other illnesses. These claims originally arose in relation to high voltage electric power lines and are very much in dispute in the medical and scientific arena, how- ever the best advice is to minimize your exposure to EMF to protect your health should doctors eventually decide there is a risk.
2.h. There are four fundamental facts about EMF:
2.h.1 With direct current (DC), the field strength is relatively constant and does not change.
2.h.2 With alternating current (AC), the field strength constant- ly changes.
2.h.3 The greater the current flow, i.e. the higher the amps, the stronger the field created by the current
2.h.4 The closer the conductor or electrical device is to the body the greater the exposure to the field.
MINIMIZE EXPOSURE TO EMF
2.i. All welders should use the following procedures to minimize EMF exposure:
2.i.1 Route electrode or gun and work cables together. Secure them with tape if possible.
2.i.2 Never coil the electrode lead around your body.
2.i.3 Do not place your body between the electrode and work cables. If your electrode cable is on your right side the work cable should also be on your right side.
2.i.4 Connect the work cable to the work piece as close as possible to the area being welded. (This is also a good practice to eliminate a common problem on welding - a poor work connection.
2.i.5 Do not work next to the welding power source.
ADDITIONAL PRECAUTIONS FOR
WELDERS WITH PACEMAKERS
2.j. There is no question that the fields in arc welding can interfere with a pacemakers function. Generally the interference does not permanently damage the pacemaker. Once the wearer leaves the arc welding environment or stops welding, the pace- maker returns to normal functioning. The welding arc has little or no effect on the operation of some pacemakers, especially designs that are
2.k. For a welder or anyone working around electrical equipment the selection of a pacemaker is very important. Get a doctor’s advice about which pacemaker is the least sensitive to inter- ference from welding while still being medically suitable.
2.l. In addition to the normal safety precautions, the following addi- tional procedures should be adopted by welders with pacemak- ers.
2.l.1 Use gas welding when the application is suitable.
2.l.2 Use the lowest current setting appropriate for the applica- tion. Do not exceed 400 amps. Low current
2.l.3 Do not use repeated, short welds. Wait about ten sec- onds between stopping one weld and starting the next. When having difficulty starting an electrode, do not re- strike the rod repeatedly.
2.l.4 If you feel light headed, dizzy or faint, immediately stop welding. Lay the electrode holder down so that it does not contact the work and move away from any welding being performed. Arrange your work in advance so that, if you become dizzy and drop the electrode holder it will not fall on your body or strike the work.
2.l.5 Do not work on a ladder or other elevated position or in a cramped, confined place.
2.l.6 Do not work alone. Work only in the presence of an indi- vidual who understands these precautions and the possi- ble effect welding may have on your pacemaker.
2.l.7 Do not work near spot welding equipment.
2.l.8 If you have a pacemaker and wish to continue arc weld- ing, discuss this and any other questions you may have with your physician and follow his or her advice. The doc- tor may wish to contact the pacemaker manufacturer for a recommendation. As mentioned before, the design of the pacemaker significantly affects the degree to which it is subject to interference from a welding circuit. Do not rely on the fact that you know another welder with a pacemak- er who has welded for years without experiencing a prob- lem.That welder and his or her pacemaker may be quite different from you and your pacemaker.
Oct ‘00
