Posted: Thursday, March 08, 2012 12:00 PM
Mateusz Perkowski/Capital Press
Paul Walther, of Stettler Supply in Salem, explains the function of irrigation equipment. As an irrigation system designer and salesman, Walther said he's seeing more pressure on farmers to chlorinate irrigation water for certain crops to prevent disease outbreaks.
Few standards for applying chemicals; packer requirements vary considerably
Using chlorine to kill pathogens in irrigation water may be just the tip of the iceberg in terms of new food safety requirements, experts say.
"The food safety pressure is consistent at this point," said Tom Peerbolt, research coordinator for the Oregon Raspberry and Blackberry Commission.
The potential for market disruption from disease outbreaks has produce packers looking to ratchet up food safety practices, said Paul Walther, irrigation system designer and salesman at Stettler Supply in Salem.
"They're trying to get food safety back to the farm," he said, noting that packers are requiring that growers chlorinate water as part of the USDA's Good Agricultural Practices program.
The program is voluntary, but Walther said he wouldn't be surprised if the federal government eventually makes it mandatory.
Chlorination is increasingly becoming a standard for some farmers, but the levels and methods of applying the chemical still vary widely, he said.
"It's still being dictated by the individual packers, and there's no consistency between them," Walther said.
In some cases, farmers are getting certified by third-party verifiers as being compliant with Good Agricultural Practices, said Connie Kirby, vice president of scientific and technical affairs for the Northwest Food Processors Association.
The GAP program is generally becoming more prominent, said Kirby, who agrees the standards will probably be required by the government over time.
With irrigation, crops that aren't subject to a "kill step" during processing are the highest priority for chlorine treatment, Kirby said. "The quality of irrigation water is going to depend on what the product is being used for."
Frozen vegetables are generally blanched with hot water, which destroys pathogens, Kirby said.
Fresh produce isn't subject to such a step, creating the need for chlorination, but flash-frozen fruits also benefit from such treatment because they're not exposed to heat before packing, she said.
"They're basically like a fresh produce item," Kirby said.
The government's implementation of the Food Safety Modernization Act, which became federal law in early 2011, will probably lead packers to impose further requirements on farmers, said Donna Garren, vice president of regulatory and technical affairs for the American Frozen Food Institute.
"Training is going to be really important," she said.
Under the statute, food packers and manufacturers will be responsible for monitoring their suppliers, which will prompt them to demand more thorough records on food safety practices from farmers, Garren said.
Regardless of packer expectations, the U.S. Food and Drug Administration will probably require growers to independently document their food safety plans, she said.
"It's not a document on a shelf, but something you need to be working every day," Garren said. "The day-to-day monitoring requires paperwork and record-keeping."
While steps like irrigation water chlorination may irk some growers, it's nonetheless widely accepted among growers of blueberries and caneberries, Peerbolt said.
"It's pretty much looked at as a cost of doing business," he said. "The issue has been there long enough that it's sunk in with the major growers."
Irrigation systems run anywhere from $1,200 to $10,000 for hardware, Walther said.
Farmers have three basic alternatives in deciding on a chlorination system: they can use the gaseous, liquid or solid forms of the chemical, he said.
In Walther's view, gaseous systems should be off the table because chlorine gas can accidentally be inhaled, displacing oxygen in the lungs and causing injury or death, he said.
"If you make a mistake with them, they'll kill you," he said. "I won't work with gas and I won't sell it to my customers. It's just too dangerous."
Solid chlorine in the form of tablets is safest and easiest to use, but some of the systems are expensive, depending how they're set up, Walther said.
Another disadvantage is tablet systems won't work with low-flow-rate irrigation systems, as they require at least 100 gallons per minute, he said.
As for liquid chlorine, it's safer than gas because the chemical is greatly diluted with water, but it's nonetheless corrosive, Walther said. "If you don't stay on top of it and maintain the equipment, the material just chews things up."