The standard "QB/T 2729-2005 Leather, Physical and Mechanical Testing - Determination of Horizontal Combustion Performance" specifies the test method for the horizontal combustion performance of leather materials. The standard applies to leather with flame retardant performance requirements. By clamping the specimen horizontally and igniting, its combustion rate and combustion distance under specific conditions are tested. This helps to evaluate the combustion behavior of leather under the action of fire sources to ensure its safety and compliance during use.