Fuels with a high energy density have contributed to the development of modern communities. On the other hand, fuels contain energy that, during some conditions, can result in incidents, not least within underground facilities. CNG vehicles are designed according to safety standards of UNECE, including events such as fire. In case of a fire a thermally activated Pressure Relief Device (TPRD) should empty the container before a pressure vessel explosion potentially can occur. CNG tanks are according to UNECE regulation 110 tested against a 1.65 m long pan fire. However, local fires, i.e. fires that do not engulf the entire tank, but only affects a local part of the CNG tank and not the TPRD, are not included in these tests. This paper presents fire tests of CNG containers performed both with a UNECE compatible fire source and with a local fire source. Any pressure vessel explosion and jet flames were characterized for two different types of CNG containers, namely steel and composite. In five out of six tests the safety of the CNG containers prevailed also in the event of a local pan fire (0.24 m × 0.24 m), meaning that no pressure vessel explosion occurred. In real vehicle fires, where the fire extends from its local characteristics to a more developed fire that expose the CNG containers to a larger extent, these tests support that TPRDs most likely will be activated. The experience from running these test series calls for that the fire source should be more accurately defined with regards to fuel and dimensions in the UNECE Regulation 110 and a local fire should be included.