Cylinders must have the correct DOT or United Nations (UN) markings and follow hazardous materials regulations prior to being transported. PHMSA issued the safety advisory to bring attention to ...

on DOT high-pressure gas cylinders. Only high-pressure cylinders serviced by ASFES bearing these markings are affected," the notice states. Anyone possessing one of these cylinders filled with gas ...

According to the alert, agents from the U.S. DOT Inspector ... about 5,900 high-pressure compressed gas cylinders with test dates and Requalifier Identification Number H557 in 2011 and 2012 ...

PHMSA is particularly concerned that these cylinders are not manufactured to a DOT specification or UN standard, lack certification markings as required by [PHMSA’s regulations], and are being ...