The TAPPI T 449 standard specifies the bacteriological inspection method of paper and Cardboard, aiming to evaluate its level of microbial contamination. The standard describes in detail the collection of samples, processing, selection of foster base, foster conditions and the steps of bacterial counting and analysis. Through this method, it is possible to detect whether there is bacterial contamination in paper and Cardboard and quantify the number of bacteria, providing an important basis for hygiene and safety. The standard is applicable to paper and Cardboard products with high hygiene requirements such as food Encasement and medical supplies to ensure that they meet relevant hygiene standards and safety requirements.