Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

6
Safe Refrigerant Handling
Limits (PEL), and the European Union employs two different values:
Indicative Occupational Exposure Limit Values (IOELV) and Binding
Occupational Exposure Limit Values (BOELV), depending upon the
circumstances.
In general, it is important to check whether the products one
intends to work with can be safely used in all of their considered
applications and handled in accordance with manufacturer
information. Whilst the toxicity of most refrigerants is low, the
possibility of injury or death exists in unusual situations or if they are
deliberately misused.
Exposure to refrigerant concentrations above the recommended
exposure levels can result in loss of concentration, drowsiness,
cardiac arrhythmia, and other symptoms, that can all lead to
fatality. The allowable exposure levels for some of the alternative
refrigerants are lower than those of the chlorofluorocarbons (CFCs).
As mentioned before, skin should be protected; many fluorinated
refrigerants and ammonia can irritate the skin and eyes.
Inhalation of concentrated refrigerant vapour is dangerous and
can be fatal. If inhaled, the victim should be moved to an area with
fresh air. If they are not breathing, they should be given artificial
respiration, and if breathing is difficult, give oxygen. It is important
to avoid stimulants, and do not give them adrenaline (epinephrine)
because this can complicate possible effects on the heart. Medical
help must be sought urgently.
Flammability and degradation products
A number of refrigerants are flammable under atmospheric
conditions. Flammability means that if ignited with a flame or spark,
they can sustain combustion. All hydrocarbon refrigerants are
flammable, as are some hydrofluorocarbon (HFC) refrigerants. The
refrigerants table in section 2 identifies those refrigerants which are
flammable. The refrigerant supplier will also provide information
relating to a refrigerants’ flammability.
Refrigerants table in Chapter 2 4
Depending upon the characteristics of a particular substance,
the consequences of ignition can be severe, and therefore it is
essential to take the appropriate precautions whenever designing,
constructing or working on a system that uses flammable
refrigerants.
Whilst many CFC, hydrochlorofluorocarbons (HCFCs) and HFC
refrigerants are not flammable under normal conditions, they can
become flammable when under pressure and mixed with air and/or
oil. Because of this potential, the refrigerants should never be mixed
with air in tanks or supply lines, or allowed to accumulate in storage
tanks, and sources of ignition should also be avoided.
Even if the conditions are such that CFC, HCFC and HFC
refrigerants are non-flammable, these substances will decompose
at high temperatures such as those associated with gas flames or
electric heaters.
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