Test agencies raised concerns about hydrogen fuel safety testing. Agencies were concerned they might not know adapter material and fitting configuration in advance of performing the test. One agency suggested adapter material should at least be the same strength as original valve material. Another agency expressed concern that adapter materials could be affected by hydraulic fluid. Most test agencies agreed there are likely no issues with pressure and temperature development of test fluid from small diameter supply lines. One agency stated flow restriction would create high temperatures that would undermine the cold cycling test. Another agency suggested pressure drop in supply line(s) can be accommodated by mandating a 1 to 2 second hold at maximum pressure during a cycle.