Modern Steel Construction • June 2021 • Environmental Transparency

The low environmental impacts of fabricated structural steel have been reaffirmed, and the most up-to-date associated documentation is now available for use.

SOME OF YOU MAY REMEMBER a time when a box of crackers didn’t have a nutrition label prominently displayed on the outside.

While tastiness no doubt played a factor, you probably also wanted to choose crackers that were healthier for your body—but you were left to weigh the nutrition claims made by the cracker makers. It’s a good thing that in 1990, the FDA mandated nutrition labels be displayed on food products.

Similarly, the building construction industry is increasingly interested in the environmental impacts associated with the products that end up in our built environment—and including a nutrition label of sorts. In fact, disclosing those impacts may actually be a hard and fast requirement during a project when seeking a green building certification like LEED, complying with codes and standards, or even when meeting customer-specific requirements— e.g., large technology companies have begun adding standard environmental impact language to their specifications.

As a service to our members, AISC produces three industry-wide environmental product declarations (EPDs) for fabricated steel products that can be used to satisfy project requirements. The EPDs are valid for five years from the date of issue; fabricated hot-rolled structural sections and fabricated steel plate EPDs were reissued on March 31, 2021, and a fabricated hollow structural sections EPD will be reissued in December 2021. Below are some common questions and answers regarding EPDs.

An EPD is a document that reports a standard set of environmental impacts occurring during a product’s life cycle. The results come from a standardized methodology aptly called lifecycle assessment (LCA). Rules on how to produce a fabricated structural steel EPD in North America are found in the UL document Product Category Rule (PCR) Guidance for Building-Related Products and Services, Part B: Designated Steel Construction Product EPD Requirements.

Here’s where the nutrition label analogy starts to make more sense. Let’s use the example of a hot-rolled W-section. That beam—which is created from 93% recycled scrap material (cars, appliances, toasters, etc.)—was melted in a modern electric arc furnace (EAF) and rolled at a mill, traveled either to a service center or went straight to the fabricator, and then received the finishing touches (cutting, drilling, welding) at the shop. Those three LCA stages are referred to as A1: Raw material supply, A2: Transport, and A3: Manufacturing. The A1 values for fabricated structural steel include all the “cradle to mill gate” impacts, averaged from American steel producer data. A2 average transport values are based on common steel supply chain distances and modes of transport. A3 values are based upon an AISC member survey of environmental impacts such as electricity and welding consumable usage.

Overall, the values are virtually unchanged. Close observers will note slight increases in the A1 and A2 values, but these are due to changes in required LCA background datasets rather than real changes in impacts. For example, electricity use is now based on regional power grid data rather than a national average. The A3 value for average fabrication impacts has decreased but within what one would consider an acceptable margin of error for an estimate such as an EPD.

Our third-party-produced and verified numbers show that 90% of the environmental impacts of fabricated structural steel occur before it leaves the mill, with less than 10% attributed to fabrication. (Also, keep in mind that the majority of steel’s carbon footprint can be attributed to the electricity used to heat the electrodes that melt the scrap in an EAF—and as national, state, and local municipalities begin to use more green energy, that carbon footprint will continue to drop.) Not only that, but the fabricator doesn’t control the design of the steel project, which can have a significant impact on the effective carbon intensity per ton of fabricated structural steel. For example, a project with heavy sections and low labor needs will have a much lower impact per ton than a project with light sections and high labor needs. American fabricators are already largely efficient in terms of energy use and scrap recycling, and differentiating environmental impacts between them isn’t an effective or appropriate strategy.

AISC member fabricators provided the data for the study and are therefore represented by our EPDs. So specifiers who want contractors that transparently disclose their environmental impacts should specify the AISC industry-average EPDs or its equivalent in their bid packages. Sample specification language is provided at aisc.org/epd.

AISC member fabricators have the confidence of knowing they can disclose the impacts of fabricated structural steel to meet project requirements. As with sample specification language, the EPDs are published for use at aisc.org/epd.

In the end, it’s all about transparency. Whether you buy crackers because they’re delicious, because they’re gluten-free, because they’re low in sodium, or any other reason or combination of reasons, a nutrition label allows you to make an educated, informed decision about what you’re buying and what you’re eating. It’s the same with EPDs for fabricated structural steel or any other material or product going into a building, from windows to carpet tiles to lighting. And when it comes to the next project you work on that has high environmental standards, you won’t just be telling your teammates that steel has a relatively low impact. You’ll have the proof.

In addition to the EPDs, you can learn more about steel and sustainability in general at aisc.org/sustainability.

Max Puchtel (puchtel@aisc.org) is AISC’s director of sustainability and government relations.