Over the past several weeks, thousands of articles, blog posts, tweets and even Facebook statuses have weighed in on the debate over Lean Finely Textured Beef (LFTB), now commonly known as “pink slime.” One place you won’t find any mention of the product, however, is on a ground beef label — or any meat label, for that matter.

That may be about to change.

As the nation’s largest manufacturer of LFTB, Beef Products Inc., reels from the consumer revolt against its product and state and local politicians work to help the company recover, the national discussion has turned to labeling.

On Monday, the U.S. Department of Agriculture (USDA) said it would approve requests from ground beef product makers who want to voluntarily label products containing LFTB.

Last Friday, U.S. Congresswoman Chellie Pingree (D-ME) and 10 co-sponsors introduced a bill that would require beef products that included LFTB to be labeled, and Reps. Sam Farr (D-CA) and Rosa DeLauro (D-CT) urged USDA to update beef labels “to note whether or not the product contains processed meat filler, and, if so, which filler(s) are in the product.”

So, why isn’t “LFTB” or “ammoniated beef” or “centrifuge-separated ammonia-treated beef” already labeled when added to ground beef?

(Were it up to satirical news anchor Jon Stewart of The Daily Show, LFTB might be labeled “ammonia-soaked centrifuge separated byproduct paste.”)

In a USA Today Op-Ed, former USDA Food Safety and Inspection Service administrator Dr. H. Russel Cross declared that “There is no need for labeling LFTB — because nothing is being added that is not beef.”

Likewise, in a recent video to help combat “a frenzy of misinformation” about LFTB, American Meat Institute spokeswoman Janet Riley added a similar justification for not labeling LFTB: “Both citric acid and ammonium hydroxide are natural processing aids, not additives or ingredients because they don’t remain in the product.”

But ammonia does remain in LFTB: A BPI spokesperson told Food Safety News that the company’s product contains between 400 and 500 parts per million (ppm) ammonia. According to microbiologist Gary Acuff, untreated ground beef naturally contains somewhere in the neighborhood of 100 to 150 ppm of ammonia.

LFTB defenders often refer to a “puff” of ammonia gas meant to kill pathogens that may be on the meat, but that puff appears to effectively leave behind four times the normal amount of ammonia.

To raise the pH of the product high enough to kill bacteria, BPI says it takes beef from 5.7 or so, where it naturally is, to 8.5. (For those rusty on their chemistry, that’s like going from the slight acidity of black coffee to the alkalinity of baking soda).

When it leaves the facility in a large frozen brick it likely drops closer to pH 7.5, according to the company, which leaves the product about 100 times more alkaline than before it was treated. (According to some who have handled LFTB first-hand, the product still smells of ammonia at this point, though most residual ammonia dissipates or dilutes in the ground beef mixture once the product is thawed and mixed with more traditional ground beef at 10 or 15 percent.)

BPI’s process also changes the texture of beef. “It in fact takes on a different texture. And that is a fine texture, which is very descriptive in its name,” said BPI spokesmen Craig Letch at a press conference featuring three governors and USDA Under Secretary for Food Safety Dr. Elisabeth Hagen.

What’s more, according to a 1995 study on LFTB by Ying He and Joseph Sebranek of Iowa State University, LFTB contains more serum and connective tissue proteins and less myofibrillar proteins than muscle meat, giving it a softer texture.

As Acuff sees it, the texture difference is actually a big part of LFTB’s image problem.

“People look at it and say ‘that doesn’t look like meat’ and that’s because of the texture,” he said. “I think people don’t have a good idea of how ground beef is made.”

Acuff, who leads the Texas A&M Center for Food Safety, explains that after the trimmings go through BPI’s process they no longer look like a traditional ground beef input: “It doesn’t look like ground beef and it certainly doesn’t look like trimmings. It looks like paste — but it’s all going to get ground up.”

So if LFTB contains added ammonia, is 100 times more alkaline, and has both a different texture and sometimes smell, why isn’t it labeled as a component when it’s thawed and mixed in ground beef? Because both the U.S. Department of Agriculture and the U.S. Food and Drug Administration have decided that ammonia is not an additive, but a processing aid.

The decision, however, was not without controversy. There was opposition within the USDA on the issue, as the New York Times reported in 2009, “department microbiologist Gerald Zirnstein, called the processed beef ‘pink slime’ in a 2002 e-mail message to colleagues and said, ‘I do not consider the stuff to be ground beef, and I consider allowing it in ground beef to be a form of fraudulent labeling.’ ‘”

There are other experts in the field who take issue with using ammonia in beef processing because it is known to mask the rancidity and lock in the color of meat. The process can disguise rancidity through both smell and color, which is reminiscent of the controversy over using carbon monoxide in meat packaging to keep meat red, even past its expiration.

According to the FDA Code of Federal Regulations, processing aids are substances used as manufacturing aids to enhance a food’s appeal or utility and are not required to be labeled because they do not technically alter the composition of the food.

Some processing aids, including ammonium hydroxide, are also considered “incidental additives” — substances that get left over in food at insignificant levels and do not change the food’s overall function.

Many in the industry do not believe LFTB should be labeled. “Beef is beef” has become the mantra of the American Meat Institute in the past week.

One of the major concerns is that if USDA were to require labeling for ammonia-treated LFTB, it might open the floodgates to labeling a plethora of processing aids and other compounds used in meat processing that might show up at low levels.

Acuff has been very supportive of BPI. He was the one of the scientists featured at the press conference last week, and he doesn’t believe LFTB should be labeled (“It really meets the requirements for a processing aid”), but he was also quick to point out that “consumers are never wrong.”

“They can be misinformed,” he said. “But ultimately they get to decide. It’s just too bad this all wasn’t discussed before people lost their jobs.”

Though it’s probably a safe bet USDA won’t require it anytime soon, consumers demanding an LFTB label at the grocery store look like they’re going to get it.

James Andrews and Gretchen Goetz contributed writing and research to this report. This story was updated to reflect that Dr. Gary Acuff was not the only scientist on the press conference panel (Dr. Elisabeth Hagen, Under Secretary for Food Safety at USDA also made remarks).