Clear Food, a subsidiary of food analyzation startup Clear Labs, found that human DNA is present in 2 percent of hot dog and sausage brands, according to a recent study.

The study also found that two thirds of the samples containing human DNA were advertised as vegetarian and almost 15 percent of products examined contained ingredients that differed from those included on the label.

“The food industry has been a black box for too long. Food consumers have to trust that food labels are accurate, but that isn’t always the case,” said Sasan Amini, Clear Labs CEO and co-founder, in a press release. “We’ve found a 10-15 percent rate of discrepancy between labeled ingredients and actual ingredients across our internal tests to date.”

The Clear Food study collected 345 samples of hot dogs and sausages — veggie dogs, sausages, and old-fashioned, all-beef hot dogs — from 75 different brands at 10 different retailers, according to their statement. They found that 14.4 percent of the samples were problematic in some way, due to ingredient substitution, addition, or hygienic issues.

“Substitution occurs when ingredients are added that do not show up on the label. Hygienic issues occur when some sort of non-harmful contaminant is introduced to the hot dog, in most cases, human DNA,” said Clear Food in their study.

Pork was found in 3 percent of samples, the majority of which were in products advertised as chicken- or turkey-only, especially problematic for people who avoid pork for religious reasons. In products not supposed to contain them, 10 contained traces of chicken meat, 9 pork, 4 beef, 3 turkey, and 2 lamb.

Vegetarian products were another source of issue in the study. Besides frequently containing human DNA, 67 percent of the hygienic issues within the samples were caused by vegetarian products. Ten percent of all vegetarian samples contained meat; Clear Food found chicken in a ‘vegetarian’ breakfast sausage and pork in a ‘vegetarian’ hot dog. Based on their study of retailers, they advise that vegetarians buy their products from Trader Joe’s.

“While some of these substitutions, hygienic issues, other variances, or off-label ingredients may be permitted by the FDA, our scientific disclosure allows you, as the consumer, to decide whether the variance or problems meet your personal standard in your buying decision,” Clear Food says in their study.

The overall best retailers for hot dog and sausage products are Target, Walmart, and Safeway, and the top brands are, in order, Butterball, McCormick, Ekrich, and Hebrew National, who all received a ‘Clear Score’ of 96, meaning ‘highest quality, great value, and safe.’ Clear Food says is it promising that there are “a number of hot dog manufacturers, large and small, that are producing high-quality hot dogs with integrity.”

Amini, in the press release, added that she and her co-founder “started Clear Food to pave the way for consumers to make more informed choices about what they eat while rewarding companies and products with integrity — those that are what they say they are.” Clear Food was designed to be the customer initiative division of Clear Labs, and aims to reveal issues with food and ways to ensure food matches the advertised quality.

Clear Food will release findings of their studies each month for free to the public on their website, ClearFood.com.