The industry of blasting and coating has many inconsistencies with using appropriate breathing air lines.
Standards vary in different countries as to what hose joiners or couplings are acceptable and will not come apart easily.
CORRECT CONNECTION STYLE FOR A BREATHING AIR HOSE
The CEJN fittings are designed with a unique ‘Double Action’ which prevents accidental disconnection. This is very important, so you don’t lose your air if you snag or pull the breathing air hose.