WHAT ARE WE EVEN TESTING FOR? THE CONTAMINANTS YOU DON’T WANT IN YOUR PRE-ROLL

Kylie Chancer Graham
Jan 22
4 min read

Most brands are just hoping to pass compliance.

At Pure Cones, we’re asking: Why are we even testing for these things in the first place?

HERE'S THE ANSWER:

Because they’re dangerous.

Because they’re everywhere.

And because once you know what you’re actually inhaling, “just passing” a COA starts to feel like the bare minimum.

In this post, we’ll break down exactly what we’re testing for—and why it matters. From the heavy metals hiding in paper pulp, to the pesticides no one talks about, to the toxic compounds created only when something is burned, we’re laying it all out.

WHY HEAVY METALS ARE SUCH A BIG DEAL

One of the reasons heavy metal testing is such a headache is because it's necessary.¹The cannabis plant is a hyperaccumulator—which means it absorbs heavy metals from its environment. That includes soil, fertilizers, water, and even the equipment used during processing.

Now imagine running that flower through a cone made from paper that’s already contaminated.

We’re not just talking about possible exposure—we’re talking about compound exposure. Burn that joint, and you’re inhaling a mix of everything the plant and the paper were exposed to.

THE “BIG FOUR” HEAVY METALS WE TEST FOR:

Lead – linked to neurological damage and developmental toxicity
Cadmium – can damage kidneys, bones, and respiratory systems
Arsenic – a known carcinogen, also associated with cardiovascular disease
Mercury – neurotoxic, even in tiny amounts

These four are harmful on their own—but when inhaled through combustion, their toxicity is amplified. This is exactly why they’re included in most compliance panels.

But there’s another metal worth mentioning:

Chromium—often overlooked, but highly toxic when inhaled in its hexavalent form (Cr(VI))² And there are very few cone papers that passe that test.

THE PESTICIDES NO ONE TALKS ABOUT (BUT EVERYONE SHOULD)

If heavy metals come from the environment, pesticides are often added on purpose.

Rolling papers are often sourced from large-scale pulp suppliers around the world. Many of these suppliers use pesticides during raw material cultivation or post-harvest processing to prevent mold, pests, or bacterial growth during transport.

And unless that paper is fully panel-tested? You’ll never know what’s in it.

One of the biggest culprits?

2-Phenylphenol (2-P) A chemical preservative and fungicide—commonly used to prevent mold on citrus fruit. In pre-roll papers, it’s been found at measurable levels even in “clean” cones.³

It’s rarely tested for in cannabis compliance panels. But when burned and inhaled, 2-P has been associated with respiratory irritation and possible carcinogenic effects.³

And it's not just 2-P.

Other pesticide residues, like cypermethrin and bifenthrin, have been detected in various papers, glues, and tips used across the pre-roll industry. None of these are tested by default in most U.S. markets—and yet they can show up in your final product with zero warning.

We don’t think that’s okay. So we test for them anyway.

MOLD, BACTERIA & OTHER THINGS YOU DON’T WANT IN YOUR LUNGS

When people think about contamination, they usually picture chemicals. But microbial threats are just as serious—and they’re often overlooked when it comes to cones.

Think about it: papers are stored, shipped, and handled in bulk. If there’s any moisture, any improper storage, or even just exposure to poor air quality during manufacturing or transport? You’ve got a problem.

We’re talking about:

Aflatoxins – toxic compounds produced by certain molds, known to be carcinogenic and immunosuppressive
Ochratoxin A – another potent mycotoxin that can contaminate plant-based materials
Aspergillus species – mold spores that have been linked to lung infections⁴
E. coli (STEC) and Salmonella – bacteria that can end up on materials through poor handling or sanitation

These microbes don’t just exist—they can thrive in the right environment. And when burned? Some transform into airborne toxins.

The problem? Not all states require microbial testing for pre-roll papers.

The solution? We do it anyway.

WHAT PURE CONES ACTUALLY TESTS FOR—AND WHY

If Pure Cones followed only the minimum requirements, we’d still “pass.” But that’s not enough.

We test for more because we know that passing a COA doesn’t mean you're in the clear. It just means you didn’t fail the basics.

OUR EXPANDED TESTING PANEL INCLUDES:

Heavy Metals – lead, cadmium, arsenic, mercury, and chromium
Pesticides – including 2-Phenylphenol (2-P), cypermethrin, and other off-panel residues
Mycotoxins – aflatoxins and ochratoxin A
Microbials – Aspergillus, E. coli (STEC), and Salmonella
Residual Solvents
Glue & Ink Safety – we use acacia (a natural, plant-based gum) and soy ink—both clean-burning and food-grade

And most importantly: we test the paper before it’s rolled, filled, or sealed. No flower to dilute the data. No mystery compounds hiding in the tip or adhesive. Just the truth.

We know exactly what’s in our cones—because we asked the lab to prove it.

FINAL THOUGHTS: CLEAN SHOULDN’T BE OPTIONAL

You wouldn’t smoke flower that tested hot for lead or mold. So why roll it into paper that hasn’t been tested at all?

Most brands don’t ask questions about their cones and most suppliers don’t offer answers.

We do both.

At Pure Cones, we believe clean, tested, fully compliant pre-roll materials should be the baseline—not the exception. That’s why we’ve gone further than anyone else to vet our paper, our glues, our crutches, and everything in between.

So the next time you ask, “What are we even testing for?”

You’ll know. And you’ll know we already took care of it.