Breathing Apparatus Regulations

Scuba is an acronym for "self-contained underwater breathing apparatus" and this vital equipment comes with some life-saving regulations. Each scuba tank, reports editor of "Scuba Diver Info" Conrad Blickenstorfer, has a series of codes and a series of inspection and testing stickers.



A reputable dive shop won't refill a tank that doesn't fulfill the regulations or pass these inspections.

  1. The First Row of Codes

    • Your tank is your lifeline

      The first and second markings on the first line of codes tell you what agency is in charge and what material the scuba tank is made of. 3A and 3AA stand for steel and AL stands for aluminum; DOT stands for the U.S. Department of Transportation.

      The third marking on this row is very important: it tells you how much air can go into the breathing apparatus. The service pressure is shown in pounds per square inch (psi), explains Blickenstorfer. Steel tanks may have a plus sign next to this number because some of them may be filled to 10% higher than the service pressure listed. Aluminum scuba tanks are not ever filled above the psi listed.

    The Second Row of Codes

    • Breathing apparatus must be visually inspected every year in the U.S.

      A second row of codes is found on your scuba tank. This row includes the manufacturer's name, a serial number and the hydrostatic test dates.

      Hydrostatic test regulations vary among countries but they are required every five years in the U.S. A certified technician determines whether the scuba tank is structurally sound and can withstand pressure and if so, places a dated sticker on the tank.

    Visual Inspection Stickers

    • A certified technician must hydrostatically test your scuba tank periodically

      Visual inspection regulations vary among countries too, says Blickenstorfer. The U.S. requires that scuba tanks get a visual look over by a trained technician every year. The technician looks for bulges, cuts, dents, stress lines and other erosion and defects on the tank and valve and checks for manufacturer recalls. If all looks well and the hydrostatic inspection sticker is up to date; the technician applies a current visual inspection sticker to your breathing apparatus.