June 10, 2025

This has been a nightmare for us, but at least after nearly 8 months we finally have definitive testing results to share and a story to tell, so let's get right to it!

After extensive testing, we can state unequivocally—NO—Fatworks tallow does not contain phthalates. And never did!

Why are we even having to say this?

In November 2024, a controversial affiliate blogger published a post claiming that our Organic Beef Tallow contained phthalates. The damage to our reputation has been severe and entirely undeserved, costing us revenue, customer trust, and no small amount of emotional strain.

Sadly, some of our less scrupulous competitors seized the opportunity to discredit us, capitalizing on her misinformation.

Since then, we’ve conducted over 20 tests for phthalates across multiple lots of both our Organic and non-organic Grass-Fed Beef Tallow—in glass jars and in plastic buckets. All tests were performed by independent laboratories at the parts-per-billion (PPB) level (and in some cases, parts-per-million as well). Every single one came back with no detectable phthalates.

Not low phthalates — NO PHTHALATES.

So yes, unfortunately, it seems that Fatworks—and our customers—have paid the price for what we’ll call blog science. There is nothing in the cattle’s diet, nor our manufacturing process, that would introduce phthalates. In fact, quite the opposite—we’ve always gone to great lengths to ensure there’s no plastic in our system at any stage. For a blogger to imply otherwise without a thorough investigation is both misleading and irresponsible.

That’s the short version—and really, all you need to know if you're wondering whether our products contain phthalates (they don't). But if you’re up for a deep dive, feel free to read on…

As you probably know, Fatworks has spent the last 15 years leading the healthy fat movement. We are the literal pioneers of the animal fat space. Creating clean, responsibly sourced, nourishing fats has always been our mission, and we take that responsibility more seriously than anyone—especially the blogger.

For months, we repeatedly requested lab details and test results from the blogger so we could properly evaluate the data, conduct our own testing, and communicate transparently with our customers.

We even reached out to the phthalate experts she cited as consultants on her blog. It turns out that while these consultants may have expertise in the harmful effects of phthalates, none of them were involved in designing, implementing, or reviewing the testing methodology prior to publication.

If her goal was truly to help us eliminate phthalates from our fats, we fail to understand the delay—or the refusal to collaborate.

Here’s where things get interesting.

The blogger tested a single jar of our Organic Beef Tallow—and here’s the twist: it was just one week from expiration, meaning it had been sitting in the jar for 357 days. Yet, by her own admission, several of the other brands in the “study” were much, much fresher—some less than 30 days old.

This isn’t speculation; it was confirmed by the blogger herself and further corroborated by the lab she used. On her blog, she states that jars were purchased between August 2023 and August 2024. But the lab confirmed that all testing occurred at the same time—in August 2024.

In other words, our nearly year-old jar—stored in a hot Amazon warehouse—was tested alongside freshly packed products, with no controls whatsoever for age or oxidation.

We have no documentation verifying the integrity of the vacuum seal on the jar. Given this, oxidation or degradation becomes a very plausible explanation.

Despite surrounding the blog with so-called “experts,” this was anything but a controlled scientific study.

That’s why the director of the lab that performed her testing (Symbio Laboratories US) told us the following, directly via email:

“I could definitely see the oxidation and degradation of the oils into free fatty acids and other smaller solvent molecules could increase the solubility of the phthalates in the oil, and therefore cause more leaching. I could also just see the fact that the oil having more time to leach the phthalates out of the container could increase phthalate concentrations in the oil.”

Simply put: Her “study” failed to control for the one factor most likely to cause phthalates to leach from the plastisol lid: time. Had the other brands been tested a week before their expiration date, the lab believes they could have shown high phthalate levels as well.

Though we intended to retest with the same lab for consistency, the blogger’s delay in responding meant that by the time we followed up, the lab had stopped offering phthalate testing and had returned to its original focus: pesticide analysis in cannabis.

Instead, we chose what we believe to be a far more qualified alternative—labs that specialize in polymers and plastics. We felt this was the more appropriate field for accurate phthalate analysis, even if it was a bit more expensive.

We were also informed by the lab that had performed the original testing that there was a chance only the top layer of the jar was sampled, rather than the full contents. The plastisol lid liner (used in all the tested products, by the way) sits at the top of the jar and can leach phthalates into that upper layer if conditions like oxidation or extended storage are present.

In other words, if phthalates were present, they would likely be concentrated near the lid—not evenly distributed throughout the jar. And according to the lab, that’s likely where the sample was taken from, though they admitted they couldn’t say for certain.

Why that wouldn’t be documented or confirmed is, frankly, beyond us.

To obtain a valid phthalate reading, the entire jar must be melted and thoroughly mixed before testing. Failing to do so risks sampling only the surface layer, which can lead to a distorted, misleading result that doesn’t reflect the product as a whole.

That said, in the interest of transparency and comparison, we replicated her lab’s flawed sampling method on some of our own jars—and even then, the results still came back with no detectable phthalates.

As many readers of the blog have pointed out, the other two Fatworks products tested in the “study”—our Grass-Fed Lamb Tallow and Grass-Fed Bison Tallow—were among the lowest in the entire cohort (!). And yet, the blogger didn’t think to re-test the obvious outlier: our Organic Beef Tallow?

Compounding matters, her impartiality is—shall we say—highly questionable, as she promotes a competing tallow brand that she tested fresh, as an affiliate.

We believe this reflects a shocking level of negligence—and shows exactly what happens when bloggers and affiliate marketers play scientist.

Simply put, there is no plastic in our rendering or processing chain, nor has there ever been. We've always prioritized the purity of our fats, long before this blogger ever entered the picture.

Ironically, Fatworks is now the only tallow company that actively tests for phthalates.

Since the publishing of her blog, we’ve tested over a dozen jars and pails from different lots. Every single test has come back non-traceable (NT) for phthalates.

Just as a point of fact, a proper phthalate test at parts-per-billion sensitivity—from a reputable lab—costs around $10,000 to set up. As a small family-owned company, this is a huge cost for us. We mention that not to complain (although we’re certainly not thrilled), but to emphasize our commitment:your trust in our purity means everything.

We know that’s a lot—but we feel it’s important for any concerned customers to understand the full story.

Fatworks built an impeccable reputation over 15 years, but the actions of one irresponsible (and frankly, malicious) blogger have caused reputational harm that’s difficult to even quantify.

We thank you for making it to the end of this FAQ—we wish we never had to write it in the first place.

At this point, to be quite blunt, your choice is between a sensationalist blogger who profits from promoting a competitor while publishing negligent “studies,” or a company that has invested in extensive phthalate testing—and more importantly, spent 15 years bringing real, healthy fats back to the mainstream—long before any of the other companies in this so-called “study” even existed.

Hope that helps. And please—let us know if you have any other questions regarding the study.

Bonus Drama!

As a final note, we feel it's important to point out a deeply concerning inconsistency in the Certificate of Analysis provided by the lab. When asked by Mamavation to provide the lab results, the above picture was what we received. As you can see in the image, the jar photographed is clearly labeled Bison Tallow, yet the sample name listed on the COA is “Fatworks Pure Tallow Organic Cooking Oil made from 100% Grass-fed Beef.”

So, which product was actually tested? Did the lab accidentally mix up the samples? Was the Bison Tallow mislabeled as Organic Beef Tallow? Or vice versa?

We simply don’t know—and unfortunately, the blogger has offered no clarification, nor has she conducted a re-test.

We do not believe that our Bison Tallow contains phthalates. But the fact that this kind of basic labeling error occurred on an official lab document is deeply troubling. If a lab can’t even identify which product it’s testing, how can any of the results be trusted?

This blunder only reinforces our concerns about the credibility of the entire “study,” and underscores exactly why scientific rigor, proper documentation, and transparency matter—especially when making claims that can damage reputations and mislead consumers.