First, the cell must show no combustion. During and after the penetration process, there shall be no open flames, continuous sparks, or other combustion phenomena. Brief local high-temperature reddening without flame formation will be further defined in accordance with applicable standards to ensure accurate judgment. Second, no explosion is permitted. The cell casing must be free from explosion-related characteristics such as cracking, bursting, or jetting of substances. For pouch cells, severe bulging followed by rupture and splashing is strictly prohibited.