This is a method standard for evaluating the flame resistance of paper and paperboard products with a thickness not exceeding 1.6 mm that have undergone flame-retardant treatment or processing. Its core involves applying a standard flame of a specific height (e.g., 40 mm) and duration (typically 12 seconds) to the sample under specified conditions using a Bunsen burner with an inner diameter of 10 mm. The flame resistance effectiveness of the material is then assessed by precisely measuring and recording key data such as after-flame time and afterglow time. The specialized instrument used to conduct this standard test is commonly referred to as a flame-retardant paper and paperboard combustion tester (or combustion test apparatus). It is characterized by features such as automatic ignition, precise timing, and flame height adjustment.