How Chlorine Became a Hot Commodity During the Pandemic

With all the COVID-19-induced supply chain stress over the last few years, few products were affected as greatly as chlorine. You may think you know the story of how we ended up with steep price increases and a historic shortage, but this series of unfortunate events includes far more than a fire, followed by a rise in demand. To understand it all, you have to learn how chlorine makes its way to a swimming pool.

The Journey Begins at the Chlor-Alkali Plant

Chlor-alkali plants are where chlorine products start. Salt water is electrolyzed to produce chlorine gas and sodium hydroxide also known as caustic soda. The process of electrolysis involves passing an electric current through a solution of salt water, which splits the water into hydrogen and oxygen and the chloride ions into chlorine and sodium hydroxide. No matter what form of chlorine you use on your route, it starts here.

“A [chlor-alkali] facility is sort of a huge version of a saltwater chlorine generator that you would have in a pool,” says Terry Arko, product training manager at HASA, which supplies liquid chlorine to the pool industry.

Electrolysis requires a lot of energy, so as electricity costs increased with inflation, so too did the price of chlorine.

In 2019, The Chlorine Institute reported there were 44 chlor-alkali facilities in the U.S., but the industry has seen many closures since then. The Environmental Protection Agency reported that in 2021 there was an approximate 10% decline in chlorine production amid a steady year-over-year decline. The industry peaked in 2000, making more than 14.057 million metric short tons, but by 2017, that was down to 12.3 million, according to The Chlorine Institute.

Of course, chlor-alkali facilities aren’t just serving the pool industry. The chlorine goes to all kinds of industries like water treatment, pharmaceuticals, chemicals, paper and pulp, plastic and pesticides. 

The production of chlorine and sodium hydroxide is tightly regulated by governing bodies to ensure the protection of workers and the environment. The plants are equipped with advanced safety systems to manage the release of chlorine gas and other hazardous substances, and the workers are trained to handle these materials.

Like all manufacturing, chlor-alkali plants have been hit with labor shortages, both during, after and because of the coronavirus pandemic. Because of the hazardous nature of these plants, the hiring and training process can be lengthy, as appropriately skilled labor can be hard to find.

To the Manufacturer

The raw chlorine made at the chlor-alkali plant then makes its way to be commercialized by the manufacturers we know in the pool industry. Those manufacturers will typically receive daily shipments of either liquid or gas chlorine by rail or pipeline.

“We have rail cars coming into our factories every day,” Arko says. “And we have deliveries [to our customers] timed out because of that. Which was a part of the problem in the shortage because we had rail cars that were committed to come in that didn’t show up. One happened during all the wildfires in California [July 2021] — where the tracks were … they couldn’t go. So that stopped everything.”

When you think about a fire responsible for slowing down chlorine production, wildfires probably weren’t what came to mind. Most in the industry are aware of the fire caused by Hurricane Laura that destroyed BioLab’s trichlor production facility in August 2020. 

And then, of course, there was the Texas freeze. Again, the pool industry is well aware of the effect Winter Storm Uri had on the industry — causing power shutdowns, frozen pools and equipment failure. But according to the S&P Global Commodities Insights, the February 2021 storm shut down all chlor-alkali facilities in Texas, and many Louisiana facilities were shut down or worked at reduced operations, which impacted approximately 55% of the U.S. chlorine capacity. 

One of HASA’s main suppliers also had a major electrical failure in June 2021. “They had a transformer that blew,” Arko says. “So all the power shut down. Because they need power, they can’t make their product, and they declare force majeure immediately. So they come to us and say, ‘We can’t give you product.’ ”

On top of the fallout from the electrical fire, Arko says a labor shortage in the railway industry left it without enough workers to get the train cars switched to the correct tracks. 

“We had rail cars that normally we were supposed to get in a day or two that were being held up for like four days,” Arko recalls.

Mix, Blend, Press, Fill

The chlorine has finally gotten to our pool and spa chemical manufacturers. Fortunately, the new $250 million BioLab trichlor plant in Westlake, Louisiana, was rebuilt and opened for operation in November 2022.

BioLab has multiple production facilities that specialize in creating chlorine products in different forms. For the purpose of this article, the focus will be on the trichlor manufacturing process, but Brian Trenck, manager of technical services at BioLab, says one thing people don’t realize is chlorine products are often very similar. 

“There are many products that are technically chemically the same, but have completely different directions for use on the package,” Trenck says. “Some of that’s dictated by regulations, and it also makes it easier for the customer. So being able to understand that this label clearly states that I apply it this way for one use, and then I apply it a second way for a different use. You do that through different products, even though the active may be the same thing.”

For chlorine to become trichlor it must be combined with cyanuric acid or CYA, which typically arrives at BioLab as a powder in what’s called a “super sack.” 

“It’s a 2,000-pound bag of material that’s convenient for forklifts to move,” says Jeff Gaulding, technology lead for process chemistry and product safety at BioLab. “Or it can also be provided as a slurry, which is a solid-liquid mixture. In that case, it might come on a rail car.”

“When [the] cyanuric acid in solution and chlorine are brought together under very strictly controlled reaction conditions it spontaneously converts to trichlor,” Gaulding explains. When the process is complete, the slurry is recovered and purified as a solid powder, which Gaulding says is the best form for them to be able to convert the trichlor into all its use applications.

The fine powder goes through a compaction process to create bigger chunks. Those chunks then experience a milling and sieving procedure where only granules of a specific size range are collected. These intermediates are used to produce the final commercial products at other BioLab facilities. 

Trenck says commercializing is done in two ways: as a powder, which can be more easily dispensed in small amounts by hand or in large amounts when oxidizing a pool; or in the form of a tablet or stick, which can dissolve in water over time.

Other BioLab facilities handle additional manufacturing steps, such as blending, tableting, packaging, labelling and shipping these products across the world.

For HASA to commercialize the chlorine it receives into a usable liquid, the process is similar. It combines the chlorine and sodium hydroxide it received from the chlor-alkali plant with water. That’s not enough though. 

“We purify it because from raw salt you can have other things in there like metals, and those are contaminants,” Arko says. If the final product contains contaminants, the chlorine will degrade more quickly, making it a less effective sanitizer.

HASA triple filters the mixture using giant cartridge filters and DE filters which remove roughly 85% to 90% of impurities, Arko says.

Next comes the labor-intensive bottling process. And in the summer of 2021, that labor was especially difficult to find. “You have people who are deciding that it’s too dangerous for me to go to work because of COVID,” Arko says. “Or [saying] ‘I don’t know if I like this job. I can collect unemployment and make more money than I can doing this.’ So all these scenarios come into play, and we’re losing labor.”

After the Fourth of July weekend, Arko says 12 people quit, which is almost an entire shift worth of employees. And like the chlor-alkali plants, hiring for this kind of work is a multi-step process with extensive OSHA-required safety training.

Speaking of bottling, another industry taken down by the February 2021 Texas freeze was plastics. Suddenly, bottles were also in short supply, and HASA had to pivot to find other suppliers.

But once the product is bottled, it’s trucked to HASA’s partners. And again, labor was a problem as truck drivers were also scarce due to worker shortages. In fact, HASA used to contract out all its deliveries, but as that became increasingly difficult, it started to hire more in-house drivers so they could have better control.

One final factor that prevented chlorine from ending up in the pool industry was the prioritization of other industries. With chlorine being difficult to acquire, the U.S. government stepped in and mandated who got served first. 

“We got a letter from the EPA that says you cannot sell your product to anyone but the drinking water facilities first,” Arko says. “And then if you have anything leftover you can sell that [to the pool industry].”

Never Again

The likelihood that the chlorine industry could undergo a series of events similar to what happened in 2020-21 is low. But manufacturers are doing what they can to ensure the pool industry never feels a crunch like that again. 

BioLab’s new Westlake facility has a staff of nearly 80 employees and improved production flexibility, enabling the lab to meet the high demand for pool cleaning products. Additionally, the new facility was built with enhanced safety features, which include an elevated control room, ride-out shelter, improved subcultural ratings and fire detection, as well as a new extinguishing system. “We are pleased to be welcoming our team back to our newly rebuilt facility, which is one of the most advanced trichlor production facilities in the world,” says Rich Bentley, vice president of operations for BioLab’s pool division.

We basically looked at everything that happened in 2021, and we addressed it, and we did what we could do to prepare for that happening again.”

Terry Arko, HASA

HASA has invested in its existing labor force to incentivize them to stay, not only by increasing wages but also remodeling. “We did things at the plant to make it a better place to work,” Arko says. The company also expanded its production capacity at its facilities. “We firmed up alternative suppliers. So we have some clout and priority. We ordered truckloads of new cases and new bottles. We leased a big lot next to our Northern California plant just to store the extra,” Arko explains. “We basically looked at everything that happened in 2021, and we addressed it, and we did what we could do to prepare for that happening again.”

“Part of the disruption is that there are only a handful of facilities that are capable of making these products,” Gaulding says. “These are specialty products that are widely used by consumers everywhere.”