Grab handles and security bars are one the bits of kit on a kayak that I have in the past paid little attention to. But I have found that if the design is right they are great for carrying and rescue duties. If not they can be a nightmare.
Most manufacturers use either a metal bar or some sort of climbing tape arrangement. In all cases you should periodically check your boats outfitting to ensure that they do not have any sign of damage or excess wear. All manufacturers can supply replacement parts if required.
Shane at Liquid Logic has filmed one of his Safety/Security bars being put under extreme conditions. Well worth watching.
We recently did another Security Bar test. It’s always fun so I filmed it again. The head of the screw popped at just about the same time as the insert that the bar is attached to pulled out of the plastic.