In the highly regulated semiconductor and cleanroom manufacturing industries, ensuring the safety and quality of materials used is paramount. Properly selecting products that adhere to the Factory Mutual (FM) 4910 criteria for fire-retardant plastics is critical to maintaining a secure and controlled environment. This blog post will delve into the FM 4910 standard, its rigorous testing protocol, and the essential characteristics of plastics that meet these stringent requirements. Moreover, we will explore the significance of selecting suitable materials in cleanroom applications and offer valuable recommendations for industry professionals.


Understanding FM 4910 Criteria

The FM 4910 standard comprises a comprehensive set of guidelines specifically for materials employed in cleanroom applications established by the Factory Mutual System, a globally recognized industrial insurance organization. This test standard “evaluates the materials’ fire propagation behavior, expressed as Fire Propagation Index (FPI), and potential for smoke contamination, expressed as Smoke Damage Index (SDI)” (1ANSI/FM Test protocol). This means that the FM 4910 Cleanroom Materials Flammability Test Protocol rigorously evaluates a material’s ability to resist fire propagation and minimize smoke emissions during a fire event.


What does the FM 4910 test protocol cover?

The test protocol to achieve FM 4910 compliance consists of three critical assessments to cover the Fire Propagation Index (FPI) and the Smoke Damage Index (SDI):


  1. Ignition test: During this assessment, the sample is exposed to constant external heat flux values. Different parameters are calculated during the test to help determine the material’s resistance to ignition.
  2. Fire propagation test: This procedure involves exposing the bottom of a sample to an external heat flux. This test is carried out until no visible flames and material vapors are emitted from any side of the sample. The aim is to observe if the fire will spread from the heat generated by its flame. The Fire Propagation Index (FPI) is then determined, which indicates the material’s tendency to support fire propagation.
  3. Combustion test: Similar to the other two assessments, external heat flux is applied to the sample and different parameters are measured during the test to help determine the Smoke Damage Index (SDI). Then, the SDI is calculated based on the amount of smoke produced. This index is a crucial tool in determining the extent of smoke contamination in the environment during the spread of a fire.


What do we expect to see on FM 4910-Compliant Plastics?

It is stated that “cleanroom materials shall satisfy both criteria: Fire Propagation Index (FPI) and Smoke Damage Index (SDI)” (FM class 4910), but other characteristics also make them ideal for cleanroom and semiconductor applications. These include:

  • Low Flame Spread Index: FM 4910-compliant plastics demonstrate a low flame spread index, signifying their reduced likelihood of igniting and burning rapidly.
  • Minimal Smoke Emission: These materials produce minimal smoke during combustion, reducing the risk of contaminating the cleanroom environment.
  • High Chemical Resistance: FM 4910-compliant plastics can exhibit exceptional resistance to chemicals commonly found in cleanroom environments, such as solvents and acids.
  • Durability: These products are engineered to withstand repeated use and rigorous cleaning processes without compromising their physical or fire-retardant properties.


FM 4910 Materials and Contamination

One significant advantage of using FM 4910-compliant materials in cleanrooms is their ability to minimize contamination risks. In the semiconductor industry, where even the smallest particle or impurity can impact the quality and functionality of microelectronic devices, maintaining a low degree of contamination is critical. Contamination can lead to defects in semiconductor components, affecting their performance and reliability.

FM 4910 materials offer several features that aid in reducing contamination in cleanroom environments, including:

  • Low Particle Shedding: FM-approved plastics are designed to have low particle shedding, ensuring that they do not release microscopic particles that can contaminate sensitive semiconductor equipment.
  • Smooth Surface Finish: These materials often boast a smooth surface , leaving fewer crevices and areas where contaminants can accumulate.
  • Chemical Resistance: FM 4910-compliant plastics’ resistance to chemicals helps prevent chemical reactions that could generate harmful particles or by-products.


Recommendations for  Industry Professionals

Those working in the semiconductor and cleanroom sectors should prioritize FM 4910 compliance when specifying materials for cleanroom applications and other regulated areas within the industry.

Here are some valuable tips to assist in the material selection process and ensure a secure working environment:

  • Collaborate with reputable suppliers and manufacturers who offer FM 4910-compliant plastics. They are required to meet stringent requirements and are audited regularly by Factory Mutual to ensure full compliance across the entire production process.
  • Conduct thorough research to identify the specific requirements of the cleanroom environment and select materials that match those needs.
  • Regularly inspect and monitor the performance of FM 4910-compliant plastics to ensure their continued effectiveness in fire prevention.
  • Train personnel on properly handling, maintaining, and cleaning the selected materials to optimize their longevity and fire-retardant properties.


Applications in Semiconductor and Cleanroom Manufacturing

The widespread adoption of the FM 4910 standard in the semiconductor and cleanroom industries stems from the substantial risks associated with fires in these sensitive environments. The presence of delicate equipment and volatile chemicals in these settings poses the potential for quick ignition, leading to significant safety and damage concerns. Manufacturers can significantly reduce the risk of fires by carefully selecting materials that meet the FM 4910 criteria and maintain a safer, more controlled environment.


FM 4910-Compliant Materials from Vycom

Plastics that meet the stringent FM 4910 criteria exhibit specific characteristics that make them ideal for cleanrooms and, overall, for the semiconductor industry. Now, let’s take a closer look at Vycom’s FM-approved materials and the benefits they offer: 

Vycom’s Thermax XL PVC exhibits a low flame spread index, reducing the likelihood of igniting and burning quickly. This quality is crucial for maintaining a fire-safe environment in cleanrooms. It also provides exceptional chemical resistance. Thermax XL PVC demonstrates remarkable resistance to chemicals typically found in cleanroom environments, including solvents and acids. This resistance ensures the material’s durability and longevity even when exposed to corrosive substances. Thermax XL PVC is a cost-effective option, making it suitable for projects where budget considerations are essential. Its affordability does not compromise its fire-retardant properties, making it a popular choice in various cleanroom applications.

Cleanroom PVC-C is designed to withstand higher temperatures than standard PVC, making it suitable for applications with essential elevated temperature requirements. Our PVC-C material offers low flame spread and exhibits exceptional fire resistance, providing an added layer of safety in cleanroom environments. Like Thermax XL PVC, PVC-C is highly chemical resistant, ensuring longevity and suitability in cleanrooms with corrosive substances. In addition, our selection of thickness options is highly diverse, providing complete flexibility to meet all the specific needs and requirements of the semiconductor industry.

Our specialized CP-7D (FRPP) is meticulously engineered to meet the stringent requirements of the semiconductor industry. By resisting combustion and impeding flame propagation, our fire-rated PP provides a heightened level of safety, mitigating potential fire hazards. CP-7D is ideal for wet process tools, furniture, and cabinetry construction within cleanroom environments. Its exceptional flame-retardant properties make it a reliable choice for ensuring fire safety. Also, our diverse range of thickness options allows for versatility, catering to many needs and specifications in the semiconductor industry.

Vycom offers unparalleled flexibility that sets us apart as a top-tier choice for your cleanroom needs. Our commitment to cutting-edge technology is evident in every aspect of our products. Vycom’s technical professionals can help provide guidance on material selection and fabrication based practices depending on process requirements and potential for exposure to various chemicals.

Our FM-approved materials deliver exceptional fire resistance with low flame spread and embody the robust chemical resilience synonymous with our brand. This combination of features enhances safety and reliability, making them an ideal choice for critical cleanroom and semiconductor applications.

In conclusion, adhering to the FM 4910 standard and choosing fire-retardant plastics that meet its criteria are crucial to safeguarding the integrity and safety of cleanroom applications in the semiconductor and other manufacturing industries. By selecting suitable materials, industry professionals can significantly mitigate fire risks, protect valuable equipment, and uphold the highest safety and quality standards in their cleanroom and semiconductor environments.



1American National Standard for Cleanroom Materials Flammability Test Protocol ANSI/FM Approvals 4910 ANSI/FM 4910-2013 (2021) Reaffirmed November 29, 2021 November 2021.

2Examination Standard for Cleanroom Materials Class Number 4910 November 2020