The EPA has approved limited use of flammable refrigerants
in appliances. Specifically, R32, R290, R600a, and R441a. They are only approved
for appliances with a limited charge, and the appliances must have warning labels
to tell anyone working on the equipment that the refrigerant is flammable.
However, the manufacturers have not gone out of their way to make sure the end
consumer is aware that the refrigerant inside the appliance is flammable. R32
is an HFC with an ASHRAE Safety rating of A2L, which means it is low in toxicity
but moderately flammable. You already use it without knowing it.
R32 is used in
many newer HFC zeotropic blends, including R-410A. These blends are generally
rated A1 (low toxicity and non-flammable) because the mixture will not burn with
the concentrations of R32 in them. R32 can be found at your local big-box store
in window units and portable air conditioners. You have to look pretty hard to
find it, but somewhere in the information they will tell you what refrigerant
is in the unit.
The other flammables are all hydrocarbons. They are all rated
A3 – low toxicity but highly flammable. R290 is propane, R600a is isobutane,
and R441a is a hydrocarbon blend. I have seen freezers and
refrigerator-freezers at big box stores with R600a (isobutane) for refrigerant.
Appliances using these highly flammable refrigerants have the required flammable refrigerant warning labels, but they are usually
on the back of the appliance where the service access is. If you want to know
if that shiny new refrigerator has explosive refrigerant in it you need to look
at the back. I noticed that one refrigerator with R600a refrigerant also had a paper
stating that using the appliance meant you agreed to binding arbitration as
your sole legal remedy for any problems with the appliance. I don’t know if
that manufacturer now makes this same disclaimer on all of their appliances,
but it is worth asking about before purchasing.
R290 (propane) is used on many
small and medium sized commercial refrigeration refrigerators and freezers. R441a
is used in some vending machines and smaller commercial refrigeration machines.
I will talk some more in subsequent posts about flammable refrigerants, safe
use, and safe service practices.
