News Information

Clarify the positioning of PIR materials, refine the classification of insulation performance, guide the industry to increase R&D investment, and promote the upgrading of insulation materials towards higher performance and diversification. 

Recently, an important technological innovation signal has emerged in the field of building insulation materials in our country - the new national standard GB/T21558 "Building Insulation Materials - Hard Polyurethane Foam Plastics" has been officially approved and released on December 31, 2025, and will be fully implemented on July 1, 2026. As the first drafter of this standard and the director of the building market of Wanhua Chemical Group Co., Ltd., Jin Yanli, in an interview with China Chemical Industry News, stated that the new version of the standard has achieved a comprehensive upgrade based on the 2008 version. With technological innovation leading and the safety bottom line being adhered to as the core, it will force the industry to optimize and upgrade, and develop in a standardized manner, building a standard barrier for building energy conservation and fire safety, and helping the building insulation industry in the "carbon neutrality" goal achieve high-quality transformation. 

It is reported that the revision plan for this standard was officially issued on April 30, 2025. Led by Wanhua Chemical and Beijing University of Commerce, etc., and under the guidance of the National Standardization Technical Committee for Plastics Products (TC48), a professional revision working group was formed to complete all the revision tasks. This revision closely follows the industry development needs of upgrading building energy efficiency and strengthening fire safety. It systematically optimized the problems existing in the previous version standard, such as insufficient classification and lagging technical requirements. Particularly, it achieved significant breakthroughs in two major dimensions of promoting technological innovation and ensuring building safety, becoming a "leading indicator" for guiding the industry development. 

One of the most significant highlights of the new standard is that by clearly defining the positioning of PIR materials and detailing the classification of insulation performance, it guides the industry to increase R&D investment, and promotes the upgrading of insulation materials towards higher performance and diversification. Jin Yanli emphasized that currently, building energy consumption accounts for 37% of the total energy consumption of the entire society. Insulation materials, as the core carrier of building energy conservation, their performance directly determines the energy efficiency of the building throughout its entire life cycle. And technological innovation is the key to breaking through the performance bottlenecks in the industry. 

According to Jin Yanli, the new standard has for the first time clearly defined the definition of rigid polyisocyanurate foam plastic (PIR) and its classification relationship with rigid polyurethane foam plastic (PUR), and has added specific performance requirements for PIR materials. "PIR materials have significant advantages in terms of high-temperature resistance and dimensional stability. Their insulation performance is more than twice that of traditional rock wool, and their weight is only 1/8 of that of rock wool. When exposed to fire, they carbonize and have fire resistance similar to rock wool, outperforming traditional thermoplastic insulation materials." She said that previously, due to the lack of clear standard basis, the market application of PIR materials was restricted. This standard revision has filled this gap and will stimulate enterprises' enthusiasm for R&D of PIR materials, promote their widespread application in high-end building insulation fields, and contribute to the popularization and promotion of high-performance insulation materials. 

In terms of the classification of insulation performance, the new standard has achieved a more refined upgrade. It has broken away from the single classification model of the previous version and set up 8 insulation grades (020 grade - 040 grade). The thermal conductivity requirement ranges from 0.020W/(m·K) to 0.040W/(m·K). "This subdivision meets the current demand for continuously improving building energy-saving standards and also conforms to the industry's development trend of 'low thermal conductivity, high strength, and lightweight'," Jin Yanli explained. With the advancement of the "dual carbon" goal, the insulation performance requirements for insulation materials in the market have become increasingly strict. Traditional materials are no longer able to meet the needs of high-end projects. The refined insulation classification will guide enterprises to increase targeted research and development efforts, focus on the research and production of low thermal conductivity products, solve the problem of industry homogeneity competition, promote the continuous upgrade of product performance, and also provide a clearer selection basis for design and construction units, achieving a precise match between insulation materials and application scenarios. 

In addition to promoting technological innovation, strengthening the bottom line of building fire safety is also the core focus of this standard revision. Jin Yanli stated that the fire resistance performance of building insulation materials directly affects the safety of people's lives and property. The new version of the standard further clarifies the classification requirements for combustion performance, still following the GB8624 classification method, and at the same time, it strictly requires that the products must comply with the national mandatory fire safety regulations such as GB46520, GB55037, GB50016 and GB50072. 

This requirement effectively sets a "red line" for the fire resistance of building insulation materials at the source, forcing enterprises to optimize their production processes and enhance the fire resistance of their products. It will also lead to the elimination of outdated production capacity that fails to meet safety standards. "Jin Yanli emphasized that the implementation of these standards will drive the industry to form a competitive landscape that prioritizes safety and offers higher prices for higher-quality products. This will significantly improve the fire safety level of buildings, prevent potential fire hazards at the material level, and safeguard building safety." 

This standard revision has also comprehensively optimized the product classification system, physical and mechanical properties, and labeling requirements. In the classification system, a three-dimensional grading system of load-bearing requirements, combustion performance, and insulation performance was established. The load-bearing requirements were further divided into 7 compression performance grades, precisely matching different application scenarios such as wall insulation, accessible roofs, and cold storage floors. In terms of physical and mechanical properties, the core density requirements were adjusted, encouraging the development of low-density, high-strength, and high-performance products, and a new size stability test under humid and hot conditions was added to better match the actual engineering application environment. In terms of labeling requirements, product traceability was strengthened, and it was stipulated that complete information must be marked on the packaging and the smallest unit of the product, facilitating market supervision and the selection by all parties. 

Jin Yanli stated that as a globally leading chemical new materials enterprise, Wanhua Chemical has always been deeply engaged in the field of polyurethane insulation materials. With over 20 years of technical accumulation, it has established a system innovation solution covering building envelope protection and environmentally friendly interior decoration. This time, taking the lead in standard revision, it not only reflects the responsibility of the enterprise but also represents a practical step towards promoting industry upgrading. "In the future, Wanhua Chemical will actively leverage its technological advantages to promote the implementation of the standards, popularize the innovative solutions for polyurethane building insulation, strengthen collaborative cooperation within the industrial chain, guide industry enterprises to adapt to the requirements of the new standards, optimize the production process and quality control system, and jointly promote the development of the building insulation industry towards higher quality, standardization and greenness." 

Industry insiders stated that the release and implementation of the new national standard GB/T21558 marks an important milestone in the standardization work of building insulation materials in China. It aligns with the current development requirements of building energy conservation, green buildings, and fire safety, and will provide solid technical support for the scientific application of rigid polyurethane foam plastics in the building sector. The comprehensive implementation of the standard helps to solve prominent problems such as industry performance bottlenecks, homogeneity competition, and safety hazards, promotes continuous improvement of the industry's technological innovation capabilities, and contributes to the realization of the "dual carbon" goals in the building sector and the upgrading of building quality.