Exentec US Achieves FM Approval for Large-Diameter Fume Exhaust Duct Systems Under Updated Standard

Exentec US, Inc., a leading innovator in fume exhaust duct systems, has achieved certification under the newly revised FM Approvals 4922 standard, making it the first U.S. manufacturer to receive FM Approval for duct systems exceeding 60 inches in diameter. This milestone demonstrates the company's leadership in safety and engineering excellence while providing facility owners and engineers with compliant solutions for larger duct systems such as mains and submains.

The certification covers Exentec's Fab-Tech PermaShield™ duct systems across unrestricted diameters, sizes, and vertical riser heights. This achievement reinforces the company's commitment to innovation, safety, and market leadership in the industrial ventilation sector. Jim Howard, General Manager of the Exhaust and Abatement team at Exentec, stated that this certification reflects their dedication to engineering excellence and proactive approach to evolving safety standards, affirming their role as a trusted partner for clients seeking high-performance, compliant solutions.

FM Approvals, a globally recognized certification organization, recently updated its 4922 standard to strengthen fire safety and performance requirements for duct systems. The revision introduces distinct Fire Propagation Index (FPI) classifications for both the exterior and interior surfaces of ductwork, with new testing protocols specifically targeting systems above 60 inches in diameter. These enhancements reflect a growing industry focus on rigorous safety standards and property loss prevention in industrial facilities.

Previously, the standard applied a unified FPI requirement across the entire duct system. The March 2025 revision now mandates a separate FPI rating for the interior liner, ensuring that both the external and internal components meet elevated safety thresholds. This update is particularly relevant for single-wall constructions, where the duct wall material itself must comply with the new criteria. The updated standard and Exentec's certification underscore a shared commitment to advancing duct system reliability and performance across industries.

For facility operators and engineers, this development means access to products that not only meet but exceed the latest safety expectations, backed by proven innovation and trusted compliance. The certification enables the construction of larger duct systems with FM Approved products, potentially reducing insurance costs and liability concerns while enhancing overall facility safety. Industries such as semiconductors, life sciences, energy, and data centers that rely on sophisticated ventilation systems can benefit from this advancement in safety standards.

The implications of this certification extend beyond immediate compliance benefits. As industrial facilities continue to scale operations and implement larger ventilation systems, having FM Approved products available for unrestricted diameters addresses a critical safety gap in the market. This development may influence industry standards globally and encourage other manufacturers to pursue similar certifications, ultimately raising safety benchmarks across the industrial ventilation sector. More information about Exentec's products and services can be found at https://www.exentec.net.