Author(s): Angelo Verzoni. Published on April 11, 2022.

The Big-Box Challenge

Experts say the fire that destroyed a Home Depot in California illustrates the importance of fire safety at big-box home improvement retailers, where a wide range of commodities are stored on tall racks 


On Saturday, a massive fire tore through a Home Depot in San Jose, California. Nobody was injured in the blaze, but officials expect the facility to be a total loss.

Experts say the incident highlights the importance of enacting fire safety measures at big-box stores like Home Depot and Lowe’s, where customers shop aisles more closely resembling those found in sweeping storage warehouses than in traditional retail stores. 

“We look at these a lot differently than we look at other occupancies because other occupancies, such as an office, have a pretty standard fire load you can assume and design your systems for,” said Brian O’Connor, a fire protection engineer at NFPA. “But these facilities can store a wide range of products. They can store anything from metal tools, which are nonflammable … to things such as paint, solvents, fertilizer, different plastics—things that are a lot more hazardous.”

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Investigators are still working to determine the cause of Saturday’s fire, and answer key questions like whether the building’s sprinkler system was active. 

Even when sprinkler systems are online, other factors can lead to those systems being overwhelmed by a fire. That could happen, for instance, if highly combustible materials are being stored in a space designed for less-hazardous materials, O’Connor said. “That could increase your fire hazard, that could overwhelm the sprinkler system if a fire did happen there,” he said. 

O’Connor added that in the past, fires that overwhelm sprinklers in warehouses have also been observed when they start on the roof, or in an area of the ceiling above where sprinkler heads are located, as well as in cases of arson. 

Home Depot first opened its doors in the late 1970s, experiencing huge growth through the ‘80s and ‘90s. Today, there are more than 4,000 Home Depot and Lowe’s locations in North America. 

An NFPA Journal article published in 1998 noted the unique nature of these facilities, existing somewhere in between a retail chain and a storage warehouse.

“It’s bigger than a hardware store and has more traffic than a warehouse,” the article reads. “Traditional hardware stores house products bought in larger quantities in a warehouse and bring them out as needed. In big-box stores, however, the general public has access to all of the product. Unfortunately, storage arrangements that make materials accessible to the public can also clog aisles, as can shoppers and carts. Free aisle space is not assured, as it is in a more controlled warehouse arrangement, where only employees have access to stock. Stocking operations can also block flue spaces between racks, which are critical to effective sprinkler operation.”

The San Jose Home Depot blaze comes on the heels of a fire last month that destroyed a 1.2-million-square-foot Walmart distribution center in Indiana. In that incident, the building’s sprinkler system was activated, but arriving firefighters reportedly shut part of it off, leading to speculation that there may have been a misunderstanding that the fire was under control when it was still smoldering.

NFPA recently introduced an online training course aimed at educating warehouse and retail employees on identifying and mitigating fire hazards in the workplace. The training addresses everything from the importance of only storing combustible products in areas designed for that purpose to the danger a single shopping cart blocking an aisle can introduce. Learn more about the training here.

ANGELO VERZONI is associate editor of NFPA Journal. Follow him on Twitter @angelo_verzoni.