PORTSMOUTH — Even before a fatal accident occurred at the Redhook Ale Brewery earlier this year, Tennessee brewer Chuck Skypeck began taking a close look at his supply of plastic beer kegs.



Skypeck's company, Ghost River Brewing, expanded its distribution quickly in the last three years, and it purchased plastic kegs to help meet the demand.



But after buying the kegs, the brewery owners decided to install a new safety feature at their facility in Memphis: a plexiglass shield.



Skypeck said Ghost River created an enclosure around its pressurized keg washer, with a locking door. He said it was “just a recognition that what can go wrong typically will.”



In a message on Twitter, Ghost River employee Joey Vaughan gave a more detailed explanation. It was accompanied by a photo of a broken plastic keg.



“This is why I stand behind a 1/2-inch thick Lexan blast shield when filling plastic kegs,” Vaughan wrote. “Sometimes, they blow up.”



Vaughan, who now owns a craft beer retail store in Mississippi, told Foster's he witnessed five plastic beer kegs rupture during his time as an employee at Ghost River, where he operated the keg washer.



It was only a few months after Ghost River installed the plexiglass shield that Ben Harris, a 26-year-old employee of Redhook Ale Brewery in Portsmouth, was killed by debris when a plastic keg exploded.



Harris, a newlywed expecting the birth of his first child, died April 24 when a keg he was cleaning with pressurized air exploded into two pieces. It broke apart at the seam, striking him in the head and chest.



Brewers were perplexed by the accident, which stood out as one of the only instances of a work-related keg explosion that many could recall.



However, since the accident, Foster's has learned of at least four other breweries around the country where plastic kegs have exploded while being cleaned in a pressurized keg washer.



In each instance, the breweries were using plastic kegs manufactured by a company called Plastic Kegs America.



In August, an unidentified brewery also submitted a report to the Consumer Product Safety Commission detailing explosions of two plastic kegs, with photographic evidence. Both were manufactured by PKA, according to the report.



The manufacturer of the keg involved in the Redhook incident has not been identified publicly, but a report set to be released this week by the Occupational Safety and Health Administration could shed new light on the mishap. OSHA faces a deadline of Wednesday, Oct. 24, to wrap up its investigation into the fatal keg blast at Redhook.



The tragedy in Portsmouth has also prompted the largest brewery trade group in the country to begin scrutinizing plastic kegs. The Brewers Association, which represents some 1,500 microbreweries, polled members this summer and received multiple reports about products made by Plastic Kegs America failing, according to director Paul Gatza.



The group is now soliciting information from keg manufacturers about how their products are designed and trying to determine which standards apply to beer kegs. Based on preliminary findings, Gatza said it appears there is no single manufacturing standard in use in the United States for either plastic or stainless steel kegs.



“We're not saying that plastic pressurized vessels aren't safe, but we're saying we don't have enough information about them — about how they're tested,” he said.

While plastic beer kegs have been in use in Europe for some time — ostensibly more than a decade — their introduction into the American market was largely spearheaded by a British company called CypherCo.



It opened a manufacturing operation for full-sized beer kegs in California under the name Plastic Kegs America, and has since established a headquarters in Texas.



Jim Holton, owner of Mount Pleasant Brewing Company in Michigan, said he's been using plastic kegs for about five years, ranging from the original European models to newer kegs designed by PKA when it opened in California.



“It was a great option for a startup brewery because stainless steel costs have skyrocketed,” he said.



The brewery was also suffering from theft of its kegs by people hoping to sell them as scrap metal. Mount Pleasant lost about 100 stainless steel kegs to theft in three years, he said.



Holton said he contacted PKA after the explosion at Redhook, and was assured of the product's safety.



Then on Aug. 6, one of the plastic kegs exploded while it was being cleaned on an automated machine, Holton said. One half of the keg soared upward, denting a 20-foot-high ceiling, and the bottom half slammed into the machine.



“If a brewer or a human being was standing over that keg when that happened, I see no reason why they would have survived that,” Holton said. “I think it would have been a catastrophic accident.”



After the accident, brewery workers inspected their equipment and discovered a pressure reducing valve wasn't working properly. As a result, the pressure being pumped into the keg could have reached as high as 100 psi, the maximum rating for the air compressor feeding the machine.



Plastic Kegs America indicates on its website that the product is designed to operate at a maximum pressure of 60 psi.



Holton said the brewery has now installed a double pressure relief valve and other safety components to prevent another keg from blowing out.



“Our incident was luckily that we lose a keg,” he said. “We don't lose a human life.”



At Marble Brewery in New Mexico, it was a brand new 15.5 gallon keg received with a shipment from Plastic Kegs America that exploded. The keg was being washed for the first time when it failed at the seam weld.



It burst with enough force to drive half of the keg into the 14-foot brewery ceiling, according to Marble Brewery President John Gozigian. The keg failed at the end of the wash cycle when the keg pressurizes to 30 PSI with CO2, according to an email sent by Gozigian to the Brewers Association earlier this year.



The brewery has verified that the keg washer's air and CO2 pressures were capped at 30 psi, and random tests showed kegs were reaching pressures below that level, he said.



Even if the regulators on the keg washer malfunctioned, Gozigian said, the pressure in the CO2 line tops out at about 100 psi.



Since the incident, Marble Brewery has started washing all kegs — metal and plastic — inside a steel cage, he said.



“This is a good example of what can go wrong, and in our case, it didn't cause any injuries, but it could have,” he told Foster's Friday, “so it's definitely spurred us to make some changes, and I think that all breweries really should look at their operations and make sure that their employees are safe.”



On Aug. 14, the federal Consumer Product Safety Commission received a report from an unidentified brewery regarding plastic keg failures. It states a pair of 5.2 gallon kegs from PKA burst at the seams while being cleaned during this year. The most recent incident occurred on May 18, according to the report, which is available at SaferProducts.gov.



A photograph accompanying the report shows two black kegs with their top halves removed, sliced cleanly through the center.



“We had our instrumentation inspected and it was functioning properly,” the complaint states. “Apparently there is an installed 'safety disc' that will fail prior to the keg exploding ... the safety feature was never initiated. Fortunately no injuries were sustained. I have contacted PKA about this and they have been slow to respond. I know there are numerous accounts of this and one ended in death.”



Like some other breweries using plastic kegs, Cigar City Brewing in Tampa, Fla., has constructed a new blast cage around its keg purging station.



Founder Joey Redner said in 2009, a Plastic Kegs America product blew apart at the seam while it was being washed. The new cage was installed this year after the fatal accident at Redhook in April.



Redner said plastic kegs are fairly common in Florida breweries, and few have experienced problems, to his knowledge, but he still has concerns about the product.



“The thing is that there's not a whole lot of standards about what a keg should be, from a quantitative standpoint,” he said. “Like, how much pressure should it hold before it fails?”

Englishman Jeff Gunn has been involved in keg design for nearly five decades — long enough that his recent warnings about plastic kegs have generated a buzz among brewers.



Gunn, the president and CEO of IDD Process & Packaging, Inc., was personally involved in designing the Sankey keg system, a design widely used today by manufacturers of both stainless steel and plastic kegs.



Sankey kegs were developed as a recyclable, returnable aseptic container by a development team in England in the 1950s and 1960s. They were manufactured to withstand the rigors of international shipping.



When the product was introduced in America, Gunn claims a negotiation took place between some of the largest beer manufacturers in the country and the American Society of Mechanical Engineers regarding the safety standard for Sankey kegs.



ASME was pushing for keg manufacturers to build a pressure relief valve into the keg design, but according to Gunn, the group relented because stainless steel kegs were capable of withstanding at least 600 psi without bursting.



In the end, the ASME gave its stamp of approval to Sankey kegs, so long as they were rated with a max pressure of 60 psi, and were manufactured to withstand at least 10 times that amount of pressure.



However, since then, Gunn says knowledge of the compromise struck in the 1970s has been lost, and there's no mechanism to ensure modern kegs are being built to those specifications.



“That is what has turned out to be the mystery here,” he said.



Plastic Kegs America has declined multiple requests for comment since the Redhook incident. However, the company has been in communication with customers and the Brewers Association.



Foster's Daily Democrat obtained a copy of an Aug. 15 email message sent by PKA Sales Manager Darcie Symons to the Brewers Association's internal mailing list. The message indicates the company's products have a maximum working pressure of 60 psi and that the kegs will rupture at a minimum of 90 psi.



“Based on the information Plastic Kegs America has to date, in all instances of purported failure, the kegs have either been pressurized above 90 psi or have been damaged after being manufactured and sold,” Symons wrote. “We take every report seriously and investigate all claims. Plastic Keg America extends its deepest sympathies with regard to the accident in New Hampshire.”



PKA founder Simon Wheaton declined to comment on the Redhook investigation when he was contacted earlier this month.



“I think we both realize the direction that you're coming,” Wheaton said in a phone interview, “and I think on advice I have no comment to make at this time.”

Craft Brew Alliance Inc., which controls Redhook, announced this summer that it has hired an independent investigator to probe the cause of the keg explosion in April. One factor complicating the investigation is that there were no witnesses to the 7 a.m. incident, according to CEO Terry Michaelson wrote, who said in June the company might never be able to ascertain the cause. Redhook believes Ben Harris was in the process of emptying the plastic keg that exploded in order to stack it on a pallet when it blew apart. Michaelson said the same keg emptying procedure has been performed without incident at CBA breweries around the country for years. The company has said the keg involved in the accident was not owned by Redhook or any other brewery under the CBA umbrella. It was delivered to Redhook in error as part of a delivery of empty keg returns. The keg wasn't clearly marked with the manufacturer's name, but CBA is in contact with a manufacturer believed to have produced the keg, according to Michaelson.

Although some in the microbrewing industry are casting a wary eye toward plastic kegs in light of the tragedy at Redhook, several other brewers are standing firm behind Plastic Kegs America. Bryan Hermannsson, co-founder of Pacific Brewing Laboratory in San Francisco, said the brewery has been using PKA products for about nine months, and he has no complaints. “The only bad thing about them is their sort of perception on the market,” he said. However, that perception is starting to impact the brewery's bottom line. Hermannsson said contractors who brew the company's beer have stopped filling and cleaning plastic kegs. The brewery was also required to use stainless steel kegs at The Great American Beer Festival in Denver earlier this month. The Brewers Association, which sponsors the annual event, did not allow plastic kegs this year. Jeremy Pate, an Alabama brewery industry consultant, said he's been contacted by at least one client since the death at Redhook who was seeking advice about whether to use plastic kegs. “I said, 'Well, basically, I'm not afraid of plastic kegs,'” he remembered. “I understand, basically, how they're constructed. I understand that when manually washing kegs, I would have all of my safety regulators presets well below the safety standards of those kegs. If you have plastic kegs, you cannot run and treat them like stainless steel kegs.”