"McDonald's hamburgers are only 15% real beef," reads one widely-shared photo attributed to RawForBeauty.com. "The other 85% is meat filler cleansed with Ammonia which causes stomach and intestinal cancer."
The claims are a myth, according to the company, which says it removed so-called "pink slime" from its meat three years ago.
"Lean finely textured beef treated with ammonia, what some individuals call 'pink slime' or select lean beef trimmings, is not used in our burgers. Any recent reports that it is are false," McDonald's said in statement.
The "pink slime" controversy dates back to 2011, when celebrity chef Jamie Oliver aired a show decrying its use in the U.S. The so-called slime refers to lean beef trimmings - what's left of the meat after all the choice cuts of beef are taken - that is treated with ammonium hydroxide, creating the pink hue. Ammonium hydroxide is used to kill off bacteria, such as E. coli.
The trimmings are banned from human consumption in the U.K., but the U.S. Department of Agriculture deems them safe for people to eat.
McDonald's Australia recently posted a video explaining how its beef is processed to help dispel claims about the use of "pink slime."
"We use real beef," Tracey Monaghan, director of quality assurance for McDonald's Australia, says in the video. "Specifically, we use forequarter and hindquarter trimmings... None of this pink slime stuff that everybody keeps talking about and certainly no meat fillers."
Watch the video: