Technician Safety Information

SAFETY

The refrigerant used in car air conditioners is also known as R-12. It is colorless and odorless both as a gas and a liquid. Since it boils (vaporizes) at - 21.7°F, it will usually be in a vapor state when being handled in a repair shop. But if a portion of the liquid coolant should come in contact with the hands or face, note that its temperature momentarily will be at least 22° below zero.
Protective goggles should be worn when opening any refrigerant lines. If liquid coolant does touch the eyes, bathe the eyes quickly in cold water. Then apply a bland disinfectant oil to the eyes. See an eye doctor.
When checking a system for leaks with a torch type leak detector, do not breathe the vapors coming from the flame. Do not discharge refrigerant in the area of a live flame. A poisonous phosgene gas is produced when R-12 is burned. While the small amount of this gas produced by a leak detector is not harmful unless inhaled directly at the flame, the quantity of refrigerant released into the air when a system is purged can be extremely dangerous if allowed to come in contact with an open flame. Thus, when purging a system, be sure that the discharge hose is routed to a well ventilated place where no flame is present. Under these conditions the refrigerant will be quickly dissipated into the surrounding air.
Never allow the temperature of refrigerant drums to exceed 125°F. The resultant increase in temperature will cause a corresponding increase in pressure which may cause the safety plug to release or the drum to burst.
If it is necessary to heat a drum of refrigerant when charging a system, the drum should be placed in water that is no hotter than 125°F. Never use a blowtorch, or other open flame. If possible, a pressure release mechanism should be attached before the drum is heated.

GENERAL SERVICE

Use care when disconnecting or connecting refrigerant lines; always use a back-up wrench and be careful not to over-tighten any connection. Over-tightening will result inline and flare seat distortion and a system leak.
When making pressure checks on systems having service valves, be sure valve is in the intermediate position. If turned in too far, the hose connection will be closed, a position used for isolating the compressor. When closing the gauge port, do not over-tighten the valve or damage to the seat will result.
After disconnecting gauge lines, check the valve areas to be sure service valves are correctly seated and Schrader valves, if used, are not leaking.