Abstract: Based on the national-level proficiency testing project, an in-depth analysis was conducted on the proficiency testing results of the 50 W horizontal flame test for non-metallic materials of electrical products. Through a systematic assessment of the participating laboratories’ performance in terms of test equipment, environmental conditions, and the understanding of the standard and practical operation skills of the test personnel, the overall capability level of the laboratories in this testing project and the main existing problems were revealed. The results show that most laboratories can complete the test in accordance with the requirements of GB/T 5169.16—2017 standard, while a few laboratories have deviations in key test links, ultimately affecting the consistency and comparability of the proficiency testing results.

Key words: 50 W horizontal flame, Burning test, Proficiency testing