What the M-Rating means for EZ-Path

Movement Cycling in the Y-Direction (W-L-3356)

The question of penetration movement and its impact on installed firestop products has been a longstanding and re-occurring question in the firestop industry. We have had the protocols in place to evaluate movement in joint firestop listings for many years but continued to lack similar means and methods for through-penetrations. This left designers in a strange position, they could account for movement between a wall and floor, but not between that same wall and a penetrating conduit or cable bundle that are suspended from that floor. Although similar, the dynamics of movement in penetrations proved to be more challenging to test in a consistent and re-producible fashion in the lab compared to movement in joint construction.

UL® created a task group consisting of Firestop Manufacturers and other parties to tackle the issues of expanding the existing UL1479 test standard to account for all factors of through-penetration movement. The recently announced M-Rating is the result of this combined industry effort to finally answer the through-penetration movement question. You may have noticed the new optional M-Rating already beginning to appear on firestop manufacturer’s listings alongside the long standing F, T, L, and W-Ratings.

What does this new testing development mean for devices such as EZ-Path®? EZ-Path’s ability to automatically adjust and self-seal as cable volumes change over time has been a staple in the cable pathway market for close to two decades now. The same self-sealing technology that facilities across the globe have come to rely on also made EZ-Path ideally suited for handling the requirements of the new M-Rating. Unlike competing solutions, EZPath demonstrated the ability to handle changing penetration conditions and the new requirements of the M-Rating without compromising performance or sacrificing L-Ratings. EZ-Path continues to set itself apart as the only cable pathway firestopping solution that can provide all applicable ratings (F, T, L, and M-Ratings) without compromise ensuring 100% compliance over its lifetime (See UL System W-L-3356 for more detail).

It has been a long road to expand UL1479 to develop and incorporate the M-Rating and we are excited to see what the new test method means for the industry and what new solutions it can lead to. If you’re interested in learning more about the M-Rating you can watch UL’s recorded webinar The New Movement in Firestops. If you want to find out more about EZ-Path and how it can ensure long term compliance on your next projects, check out our EZ-Path overview at