I've just been revisiting this subject. That link is to an irish website and some countries do apply differing restrictions.
EN12245 is the european directive governing construction and certification whilst inspection and testing is covered by...
BS EN ISO 11623: 2002 Periodic inspection and testing of Composite Gas Cylinders, and 97/23/EC.
-Composite cylinders manufactured to the above standard are available with a design life up to 30 years.
-If you go to the this Drager site
you can download the pdf for their CF cylinders.[>Specification>Carbon composite].
-Best-Fittings also offer these cylinders
for sale with Design Lives of 15/20/30 years by way of illustration.
-Lastly Luxfer have a useful download
... "Cylinder Fitness Check Poster". See attached pdf download... it covers what to look for, test period and a very useful explanation of all the markings to be found on composite cylinders. HTH