Safety Precautions for General Air Conditioning System

  • Wear gloves when connecting or disconnecting service gauge hoses.

  • Always wear eye protection when working around refrigerant and air conditioning systems. Since the system's high side is under high pressure, severe injury to the eyes could result if a hose were to burst. Refrigerant also evaporates rapidly when exposed to the atmosphere, causing it to freeze anything it contact. That's why it's a good idea to protect skin and clothing with a shop coat. And a bad idea to wear loose clothing or things like ties or jewelry that could get caught in the drive belts.

  • Never strike a section of copper or aluminum tubing or a heat exchanger in a charged refrigeration system. A blow from a heavy tool could easily cause the relatively soft material to rupture.

  • If you have to apply force to a pressurized refrigerant threaded fitting, always use a back-up wrench to avoid the direct transfer of excessive torque to a section of refrigerant tubing. Whenever possible, use wrenches specially designed for "1/4 inch flare nut" fittings (R-12 systems) or for 112-inch "Acme" fittings (R-134a systems).

  • Because refrigerant is heavier than oxygen, high concentrate of refrigerant can displace oxygen in a confined area and act as an anesthesia. This is particularly important when leak-testing or soldering because toxic gas formed when refrigerant comes in contact with a flame.

  • Never operate an air conditioning system without first verifying that test gauges are back seated, if equipped, and that all fittings throughout the system are snug.

  • Never apply heat of any kind to a refrigerant line or storage vessel. Always store refrigerant containers in a cool place.

  • Never allow them to sit out in the sun or near a heat source. And never expose them to an open flame.

  • Never store refrigerant drums around corrosives like battery acid. Drums may corrode and then burst.

  • Always wear goggles when working on an air conditioning system. And keep a bottle of sterile mineral oil and a quantity of weak boric acid solution nearby for emergencies ( refrigerant is readily absorbed by this  oil ). If refrigerant contacts your eyes, immediately use a few drops of mineral oil to wash them out, wash them clean with the weak boric acid solution.

  • Frostbite from refrigerant should be treated by first gradually warming the area with cool water and then gently applying petroleum jelly. A physician should be consulted.

  • Always keep refrigerant drum fittings capped when not in use. Avoid sudden shock to the drum which might occur from dropping it or from banging a heavy tool against it. Never carry a drum in the passenger compartment of a vehicle.

  • Always have the system discharged before painting a vehicle, if the paint must be baked on, and before welding anywhere near refrigerant line.