Data center fires don’t just threaten digital infrastructure. They can claim lives and put businesses at risk. Although data center fires are rare, they can and do happen. There are nearly 8,000 data centers worldwide, but what if a fire struck a facility that you built, maintained, or operated? Two recent examples demonstrate the potential consequences.

Last fall, a lithium-ion battery started a fire in an electrical control room in South Korea. The conflagration eventually disrupted the operations of a data center that provides essential services to many businesses. Today, those businesses are considering a lawsuit for financial damages caused by the outage. There’s also the tragic case of how electrical arcing near an Iowa data center caused a fire that killed electricians.

According to safety experts, data centers need to take a multifaceted approach to safety. In addition to reviewing their fire suppression and mitigation plans, operators need to harden their facilities against fire damage and update their disaster recovery strategies. As part of these efforts, facility managers can require data center construction companies to install fire-resistant gaskets with doors and panels.

UL 94 ratings and performance properties

Many data center builders and operators are familiar with the UL 94 flammability standard from Underwriters Laboratories. However, there’s a difference between UL 94 V0, which is a vertical burn rating, and UL 94 HB, which is a horizontal burn rating. There are also ratings like UL 94 V1, V2, and V3, all of which are part of the same standard. When a material passes testing, UL issues a Yellow Card.

In addition to using rubber with the right UL 94 rating, it’s important to determine if the gaskets can withstand water, heat, and steam. Most fire suppression systems in data centers are water-based, so gaskets need to resist water in both its liquid and gaseous forms. Even if a fire occurs and is suppressed before significant damage occurs, gaskets still need to resist high temperatures.

Impact resistance is an additional requirement. For example, consider the rubber gaskets that are used between metal data center panels. They need to be soft enough to compress, fill the gap between two surfaces, and form a seal. Yet, the rubber must also withstand permanent deformation. If a gasket becomes crushed from compressive stresses, seal failure may occur.

From material selection to gasket installation

In addition, data center gaskets need the right size and shape. Height and length are important measurements, but so is the width of the gap that the gasket is designed to fill. Along with these technical considerations, data center builders and operators need to think about gasket costs, order quantities, lead times, and ease of installation. There are a number of factors to consider.

First, because fire-resistant rubber is a specialty compound, it’s more expensive than a commodity material. Plus, the minimum order quantities (MOQs) can be higher than what data center builders and operators expect, and tooling charges may apply. The tools, or dies, that are used to extrude lengths of rubber take time to build, and the extrusion process itself carries lead times.


UL 94 HB EPDM sponge rubber gasket
A UL 94 HB EPDM sponge rubber gasket with spring steel clip.
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Data center operators and builders can also choose fire-resistant gaskets that are easy to install. With taped gaskets, an installer peels back a protective liner and sticks the gasket to the substrate. Gasket tapes can provide either temporary or permanent bonding, but the ones that are used in data centers need to meet the same UL 94 rating as the gasketing material itself.

Data center case study

Finding gaskets that can meet all of these requirements might seem challenging, but some data centers are using rubber seals that meet these specifications. For example, when a leading search engine needed to build more data centers, the operator asked the builder to source fire-resistant gasketing from a distributor and fabricator of industrial rubber products.

The compound the data center specified was a UL 94 HB EPDM sponge rubber with a spring steel clip for impact resistance. This black EPDM rubber has a UL Yellow Card and a product information document that lists safety and performance properties, which proves the material meets the applicable UL standard. This rubber compound also provides heat, steam, and water resistance.

Although it contains a steel clip, this elastomer still has a durometer, or hardness, that supports proper compression. Seals made of this material are designed to fit a 1/8-inch gap between panels and support the use of fire-resistant adhesive tape.

As demand for data centers continues to grow, builders and operators need to choose quality materials to protect their investments. UL 94 HB EPDM sponge rubber gaskets won’t prevent events, such as thermal runaway or electrical arcing from happening, but they can mitigate the potentially catastrophic effects should fires occur.