Science

Tastes Like Chicken

How does rubber keep getting into chicken nuggets?

Chicken nuggets
The USDA said Tuesday that meat processor Tyson Foods is recalling 36,420 pounds of chicken nuggets.
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The USDA announced on Tuesday that meat processor Tyson Foods is recalling 36,420 pounds of chicken nuggets because of consumer complaints about rubber contamination. The affected products—“White Meat Panko Chicken Nuggets” with a Nov. 26 “best if used by” date—have not been responsible for any confirmed reports of sickness, but health officials are concerned that some consumers may have the possibly contaminated nuggets in their freezers.

This isn’t the first time that consumers have found rubber in their chicken nuggets. In 2016, Foster Farms recalled 220,450 pounds of frozen nuggets found to have contained blue plastic and black rubber. That same year, Pilgrim’s Pride ordered a recall of 4.5 million pounds of whole grain breaded chicken nuggets due to possible contamination by rubber, along with wood, plastic, and metal. How does rubber keep finding its way into nuggets?

Probably from pieces of rubber or plastic breaking off food processing equipment. Only employees at Tyson would know exactly what happened in this case, and the company did not respond to Slate’s request for comment. (Update: Tyson responded after publication and confirmed the rubber was part of a seal on a piece of equipment. Its full statement is at the end of this post.) However, according to Cornell food microbiology professor Randy Worobo, this sort of contamination usually occurs when a plastic or rubber piece gets fatigued. Maintenance programs normally catch and replace worn pieces before they cause problems. But if missed, they could end up in the finished product.

When it comes to chicken nugget processing, rubber and plastic are most commonly found in paddles, seals, and nozzles. The paddles are responsible for mixing the ground chicken slurry that constitutes the body of a nugget. This mixing helps to ensure that the protein binds the meat together. “It’s just like when you take hamburger and mix it with your hand,” Worobo said.

The nozzles pump the slurry from one stage of the process to another, while the seals ensure that there’s a waterproof bond between different pieces of equipment. “There would be a lot of rubber and plastic seals in a plant that is collecting the trimmings and slimy bits of chicken to squeeze them into ‘nuggets,’ ” said Jaydee Hanson, a senior policy analyst at the Center for Food Safety.

These parts wear down with use. Normally, inspectors check for fraying rubber at the end of the day during the cleaning and sanitation procedures. Employees involved in food processing will also notify management of failing equipment. There are no laws mandating the frequency of these inspections, though it’s within a company’s best interest to ensure that it catches contaminations prior to distribution. “This is where the communication with the cleaning and sanitation crew with is really important,” Worobo said.

With chicken nuggets, it’s fairly difficult to install failsafe measures to filter out extraneous material that makes its way into the meat slurry. Magnets won’t be too helpful in attracting pieces of rubber or plastic, and the slurry can’t easily pass through fine mesh filters.

Whether or not a broken piece of equipment falling into a product causes illness depends on the size and firmness of the material. If the material is soft, it shouldn’t cause issues. However, large and rigid materials, such as plastic, can puncture the intestinal tract. Children are especially at risk of becoming sickened by larger debris that may stray into food products.

Update, Jan. 31: Tyson provided Slate with a comment after publication:

The rubber is part of a seal on a piece of equipment used to produce nuggets. Part of it was pinched during the normal process and was introduced into the blend. We have put measures in place to help prevent this from occurring again.