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Study breakdown

Hemp Cigarettes Contain Similar Metal Levels as Tobacco, with Lower Cadmium but Higher Chromium in Some Brands

Laboratory StudyModerate evidence
The takeaway

An analysis of 14 hemp cigarette brands found metal concentrations broadly similar to tobacco cigarettes, with all hemp brands having lower cadmium but several exceeding state action limits for chromium, nickel, arsenic, and lead.

Hemp cigarette consumers, public health regulators, tobacco harm reduction researchers

What the researchers found

Researchers analyzed 14 commercial hemp cigarette brands for nine metals and compared them to published data on tobacco cigarettes and little cigars. All hemp cigarette filler had cadmium concentrations below the lowest reportable level, significantly lower than tobacco. However, concentrations of other metals (beryllium, chromium, manganese, cobalt, nickel, arsenic, lead, uranium) fell in ranges similar to tobacco products, with several brands exceeding some state action limits for chromium, nickel, arsenic, and lead.

Why it matters

Hemp cigarettes are often marketed as tobacco alternatives or cessation aids, but their metal content had never been analyzed. Knowing that metal exposure risks are broadly similar to tobacco, with some brands exceeding state safety limits, is essential safety information for consumers.

The numbers in context

14 hemp cigarette brands analyzed; 9 metals measured; all hemp cadmium levels below reportable limit (significantly lower than tobacco); several brands exceeded state action limits for chromium, nickel, arsenic, and lead

How the study worked

Laboratory analysis of hemp filler from 14 commercial brands for nine metals (Be, Cr, Mn, Co, Ni, As, Cd, Pb, U). Results compared to previously published US tobacco cigarette and little cigar data. NIST Reference Material used to verify analytical accuracy.

What this study cannot tell us

Analyzed filler content only, not smoke or emissions. Metal concentrations in the product do not directly predict metal delivery to the user. Comparison to tobacco data from separate studies introduces variability. State action limits vary and may not perfectly apply to smoked products.

How to read the evidence

Moderate: rigorous laboratory methods with reference standards, but analysis of product composition rather than health outcomes.

When this study was published

2025 publication

The bigger picture

As hemp cigarettes gain market share, the assumption that they are inherently safer than tobacco products needs scrutiny. Metal contamination is one piece of a larger safety picture that includes combustion byproducts and other chemicals of concern.

Questions still open

  • What are the actual metal emissions in hemp cigarette smoke compared to tobacco?
  • Should hemp cigarettes be subject to the same testing requirements as tobacco products?

Read the original research

Comparison of selected metals in the fillers of 14 commercial hemp cigarette brands to commercial tobacco cigarettes.

Journal of cannabis research, 8(1), 11

Citation

Gray, Naudia R; Pappas, R Steven; Watson, Clifford H. (2025). Comparison of selected metals in the fillers of 14 commercial hemp cigarette brands to commercial tobacco cigarettes.. Journal of cannabis research, 8(1), 11. https://doi.org/10.1186/s42238-025-00330-7

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