Herbal Cigarettes Emit Harmful Particles Comparable to Tobacco Smoke, Study Finds

A joint investigation by the Indian Institute of Technology Gandhinagar (IITGN) and the University of Illinois Urbana-Champaign (UIUC) shows that herbal cigarettes marketed as natural, tobacco-free alternatives generate mainstream smoke that is comparable to or exceeds the toxicity of conventional tobacco cigarettes. Researchers said the results overturn the belief that tobacco-free products are risk-free and stress that combustion by-products, fine particles, trace metals and the wrapper all drive toxicity. Leaf-wrapped herbal variants were the most hazardous among the products tested.

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobaccoIIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke

The team compared two Indian tobacco brands with four herbal brands (basil, clove, cinnamon, mint, green tea, water lily, chamomile). Each product was combusted in a sealed, automated two-chamber rig mimicking human inhalation. Real-time instruments measured particle size, composition and oxidative potential (OP). Findings appeared in the *Journal of Hazardous Materials*.

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco

Sub-500 nm particles were about 20 % higher in herbal smoke than in tobacco smoke. Oxidative potential of herbal particles was markedly greater; tendu-leaf-wrapped variants showed OP roughly 49 % higher than paper-wrapped. The basil-filled herbal cigarette had the highest lead concentration among all samples.

IIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke

The study noted that several herbal brands claim benefits like cough relief, better sleep or anxiety reduction without scientific support. Researchers warned that wellness-oriented messaging may attract younger users and first-time smokers, exploiting the exemption of tobacco-free products from India’s COTPA (2003).

IIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke

COTPA regulates tobacco products with warning labels, advertising limits and public-smoking rules, but it excludes tobacco-free alternatives. Similar gaps exist elsewhere. The findings were released on World No Tobacco Day (May 31), whose theme “Unmasking the appeal: countering nicotine and tobacco addiction” highlights the need for oversight of alternative smoking products.

IIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco

The authors noted the research does not provide direct epidemiological links between emissions and disease outcomes and highlighted a broader lack of toxicological evaluation for herbal cigarettes, marking a critical gap for future study.

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco

• “Our findings challenge the widely held belief that tobacco-free means risk-free,” — Prof Sameer Patel, Assistant Professor, IIT Gandhinagar

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco

• “Emissions from herbal cigarettes are comparable to or exceeded those from tobacco cigarettes on nearly every metric we measured. Leaf-wrapped herbal variants turned out to be the most hazardous of all the samples tested.” — Prof Sameer Patel

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco

• “That finding is important because many consumers associate nicotine-free products with reduced harm.” — Prof Vishal Verma, Associate Professor, UIUC

IIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke

• “Combustion, fine particles, soot, trace metals, and the wrapper around them all matter more than what is written on the box.” — Dr P.S. Ganesh Subramanian, Postdoctoral researcher, Washington University in St. Louis

IIT Gandhinagar and University of Illinois study finds herbal cigarettes emit harmful particles comparable to tobacco smoke

The authors recommend that policymakers enact specific regulations for herbal and other tobacco-free smoking products and that further toxicological and epidemiological research be undertaken to clarify health risks.

“Herbal” does not mean “harmless”: A new study finds herbal cigarettes are not safer than tobacco