Crystal CPF High Pressure Hose and Fittings - Manual (Page 11)

Crystal Safety Guide for Using Hose Assemblies and Fittings  9
Elastomeric (o-ring) Seals
Elastomeric (o-ring) seals will eventually age, harden, wear and deteriorate under thermal cycling and compression set. Elastomeric seals should be inspected
and replaced.
Refrigerant Gases
Special care should be taken when working with refrigeration systems. Sudden escape of refrigerant gases can cause blindness if the escaping gases contact
the eye and can cause freezing or other severe injuries if it contacts any other portion of the body.
Compressed Natural Gas (CNG)
Do not inspect CNG systems using matches, candles, open flame or other sources of ignition. Leak check solutions should be rinsed off after use.