Regarding 134a, there are both pharma grade HFA-134a and industrial grade HFC-134a(usually called R134a）.
The difference is as follows:
HFA Propellant/Aerosol Propellant HFA-134A is used in medical sprays including:
MDIs (Medicated Measure Inhalers) also known as Medicated Aerosols or Asthma Sprays are used to treat asthma, COPD (Chronic Obstructive Pulmonary Disease), and respiratory infections.
Nasal spray for allergic rhinitis.
Foam spray
Oral and topical sprays (eg, nerve sensitization, tooth vitality, pain relief)
HFA-134a replaces the fully halogenated ozone-depleting chlorofluorocarbons CFC 11, CFC 12, and CFC 114 traditionally used in medical sprays, the non-ozone depleting hydrofluoroalkane HFA 134a is being phased out under the terms of the Montreal Protocol, also known as the pharmaceutical HFA-134A (P).
However, industrial grade R134a is mainly used as a refrigerant , fire extinguishing agent,solvents,etc
The industrial grade is used in refrigeration and air-conditioning etc, whereas the pharma grade is used as a drug propellant. The plant and machinery, raw material, and the process of production of both the types are same. Production of pharma grade requires further manufacturing process after R134a is produced. The difference between the two is only the level of purity, the purity required for the pharmaceutical grade meant for human consumption is minimum 99.99% (lower level of impurities).
