The express delivery industry is an important component of the modern circulation system, and is a fundamental and strategic leading industry to smooth the economic arteries and ensure the microcirculation of people's livelihoods. In recent years, China's express delivery industry has continued to develop rapidly, with emerging formats such as fresh cold chain, rural delivery, and integrated warehousing and distribution emerging. Automation, informatization, digitization, and greening have accelerated comprehensively, and the volume of express delivery business has ranked first in the world for ten consecutive years. In order to further regulate the development of the postal industry, improve the quality level of express delivery services, and provide technical support for promoting green and low-carbon development of the express delivery industry, the State Administration for Market Regulation (National Standards Committee) recently released five national standards, including "Limits for Heavy Metals and Specific Substances in Express Packaging" (hereinafter referred to as "Specific Standards"), "Express Services", and "Express Circular Packaging Boxes", focusing on the quality of express delivery services and green packaging for express delivery. Among them, GB 43352-2023 is the first mandatory national standard for express packaging in China, which will be implemented from June 1st this year. Promoting the green transformation and upgrading of the express delivery industry. Currently, China's express delivery business has achieved a significant leap from an average of 10 billion yuan per year to an average of 10 billion yuan per month. Properly handling express packaging is of great significance for resource conservation and environmental protection. Therefore, among the five national standards released this time, the "Specific Standard" is the most concerned, which clearly prohibits the use of toxic and harmful express packaging and sets safety bottom lines and red line requirements for express packaging. In recent years, the State Administration for Market Regulation, in conjunction with the State Postal Administration, has continued to promote the standardization of green packaging for express delivery. A joint working group on the standardization of green packaging for express delivery has been established, and a standard system for green packaging for express delivery has been established. In particular, in 2020, the State Administration for Market Regulation and eight other departments jointly issued the Guiding Opinions on Strengthening the Standardization of Green Packaging for Express Delivery, proposing to strive for the comprehensive establishment of a strict and binding green packaging standard system for express delivery by 2022, gradually improving the governance system for green packaging for express delivery that coordinates standards with legal policies, and promoting standards to become the "hard constraint" of green packaging for express delivery. According to Li Aixian, Vice President of the China Institute of Standardization, common express packaging is usually divided into three categories: paper, plastic, and textile fiber, such as corrugated paper packaging boxes, plastic packaging bags, and container bags made of textile fiber materials used in express transit. The specific standards released this time provide limit requirements for heavy metals and specific substances for these three types of express packaging. For paper express packaging, the "Specific Standards" stipulate the total and quantity limits for four heavy metals: lead, mercury, cadmium, and chromium, as well as the limit requirements for solvent residues and absorbable organic halogens (AOX). For express electronic waybills, a limit requirement for bisphenol A has been specifically added. For plastic express packaging, the "Specific Standards" classify plastic express packaging into two categories: non biodegradable and biodegradable. Among them, for non biodegradable plastic express packaging, the total amount and quantity of four heavy metals, lead, mercury, cadmium, and chromium, as well as the limit requirements for solvent residues and phthalates, are specified. For biodegradable plastic express packaging, in addition to the above requirements, zinc, copper