Are Printed Rolling Papers Safe? New Study Raises Alarms Over Heavy Metals
We’ve gotten smarter about what we smoke. Strain profiles, terpene content, pesticide testing—today’s consumers expect transparency. But while we’ve raised the bar for flower and concentrates, one part of the ritual has quietly ducked scrutiny: rolling papers.
That may be about to change.
A new peer-reviewed study from Lake Superior State University (LSSU) has uncovered troubling levels of heavy metals in soy-based inks used on printed rolling papers, especially those with colorful designs. The findings are already prompting industry action: Custom Cones USA, a leading pre-roll supplier, has pulled all printed papers from its inventory, effective immediately.
The Study That Sparked Industry Action
Led by Dr. Derek Wright, coordinator at LSSU’s Cannabis Center of Excellence, the study used inductively coupled plasma mass spectrometry (ICP-MS) to analyze 26 elements in commercially available rolling papers. The results were clear: printed papers—particularly those using blue, green, and purple pigments—contained significantly high levels of heavy metals like copper, chromium, and vanadium.
Dr. Wright reports that regular use of these products could expose consumers to metal concentrations up to 11 times the daily allowable inhalation limit, according to standards outlined in USP 232 and ICH Q3D. However, those standards don’t apply to rolling papers, which remain largely unregulated across most states.
A Wake-Up Call for the Industry
That lack of regulation is precisely what led Custom Cones USA to act. “This was a simple decision rooted in science and values,” says Bard from Custom Cones USA. “If we know something we sell poses a potential risk to consumers, how could we continue selling it?”
The company, which already conducts heavy metals, pesticide, and microbial testing, now considers soy-ink printed papers—including those considered food-grade—below acceptable safety thresholds. Bard emphasizes: “Inhalation is not ingestion. What’s safe to eat isn’t necessarily safe to smoke.”
The company’s consumer brand, DaySavers, will also halt development of any printed paper products. DaySavers packaging features QR codes linking to full-panel lab results—part of a growing push for transparency.
Pigment Problems and Surprising Metals
The study traced the high metal content to pigment color. Dr. Riley Kirk, a pharmaceutical scientist who reviewed the data, notes that high copper levels in blue and green pigments align with known chemistry, but are likely surprising to consumers.
“I don’t believe people would assume that it was actual copper contributing to the color,” Kirk said.
Even luxury items weren’t exempt. Gold-leaf cones contained notable levels of copper and silver. While ICP-MS didn’t fully measure gold content, follow-up X-ray fluorescence (XRF) confirmed it—raising concern given existing research linking inhaled gold nanoparticles to lung inflammation.
A Call for Transparency and Caution
Most rolling papers are not tested the way they’re actually used: combusted and inhaled. Many consumers mistakenly believe regulation ensures safety. This study shows otherwise.
“It’s time we rethink what goes into every part of the cannabis experience,” Bard said. “This is a wellness industry. That means we need to prioritize safety—even if it means walking away from flashy products.”
Custom Cones USA had already phased out trendy wraps like rose petals and palm leaves due to pesticide concerns. Now, the spotlight is on printed papers as the next frontier for consumer safety.
Rolling papers may seem minor in the broader cannabis landscape, but with pre-rolls becoming the industry’s fastest-growing category, what they’re made of—and how they’re regulated—matters.
Until regulations catch up, consumers should steer clear of heavily printed papers and lean toward brands that offer transparent testing. Because we all deserve to know what we’re inhaling.
For more about Custom Cones USA, visit customconesusa.com. To learn more about DaySavers, visit daysavers.com.
