The FIA approved standard for Safety Fuel Cells is FIA/Spec./FT 3 and FT 5. These fuel cells are only manufactured by authorised companies and bear the name of the company, specification, SAFETY CRITERIA code and date of manufacture stencilled on each cell. No other cells are approved.
The tanks have a cure date marked on them. For international motorsport the life is 5 years. They can then be rechecked and if o/k a 2 year extension period is given.
For U/K events run under MSA rules the tanks are not lifed. It is however recommended that they are sent back to the manufacturer periodically to have them checked for your own piece of mind and safety.