{"id":32863,"date":"2026-01-09T10:31:12","date_gmt":"2026-01-09T10:31:12","guid":{"rendered":"https:\/\/clearingtheair.eu\/?p=32863"},"modified":"2026-01-09T10:31:17","modified_gmt":"2026-01-09T10:31:17","slug":"lab-studys-passive-vaping-claims-dont-match-real-world-exposure-say-experts","status":"publish","type":"post","link":"https:\/\/clearingtheair.eu\/en\/post\/lab-studys-passive-vaping-claims-dont-match-real-world-exposure-say-experts\/","title":{"rendered":"Lab study\u2019s passive vaping claims don\u2019t match real-world exposure, say experts"},"content":{"rendered":"<div class=\"clear-before-content-2\" style=\"margin-top: 20px;margin-bottom: 20px;margin-left: auto;margin-right: auto;text-align: center;\" id=\"clear-542205807\"><a href=\"https:\/\/www.broughton-group.com\/nicotine?utm_campaign=43296353-Clearing%20the%20Air%20PPC%20Campaign%20-%202026&#038;utm_source=ppc&#038;utm_medium=Paid%20Ads\" aria-label=\"728 x 90 (2)\"><img src=\"https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2.png\" alt=\"\"  srcset=\"https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2.png 728w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-300x37.png 300w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-370x46.png 370w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-600x74.png 600w\" sizes=\"(max-width: 728px) 100vw, 728px\" width=\"728\" height=\"90\"  style=\"display: inline-block;\" \/><\/a><\/div>\n<ul class=\"wp-block-list\">\n<li><strong>Experts say a lab study on \u201cpassive vaping\u201d does not reflect what bystanders actually breathe in real life.<\/strong><\/li>\n\n\n\n<li><strong>The experiment used a machine to pump vape aerosol into a tiny sealed chamber, which critics say can exaggerate exposure levels.<\/strong><\/li>\n\n\n\n<li><strong>Roberto A. Sussman says bystanders inhale exhaled vapour from people, not freshly generated aerosol from a device.<\/strong><\/li>\n\n\n\n<li><strong>He also questions whether the flavour chemicals tested are representative of most nicotine vapes.<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A recent laboratory study examining how vape emissions change over time indoors has been cited as evidence of potential risks from \u201cpassive vaping\u201d. But <a href=\"https:\/\/reference-global.com\/article\/10.2478\/cttr-2025-0019\" rel=\"nofollow noopener\" target=\"_blank\">experts say<\/a> the experimental set-up does not reflect how vaping happens in everyday environments and could overstate bystander exposure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/escholarship.org\/content\/qt73h0q3sc\/qt73h0q3sc.pdf\" rel=\"nofollow noopener\" target=\"_blank\">The study,<\/a> \u201cChemical Transformation of Vaping Emissions under Indoor Atmospheric Aging Processes\u201d by Linhui Tian, Wonsik Woo, and Ying-Hsuan Lin, was published in Chemical Research in Toxicology in 2025. It investigated how vape aerosols behave when they are left to \u201cage\u201d in indoor air, including air containing ozone (O\u2083).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Roberto A. Sussman, a researcher at the National Autonomous University of Mexico (UNAM), says the experiment was competently performed but argues its conclusions should not be applied to real-world passive vaping.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">He describes it as \u201can interesting and correctly conducted experiment,\u201d but adds that \u201cits results have no relevance to assess the risks of exposure of bystanders to environmental vaping aerosols\u201d.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What the researchers did<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In the study, aerosols were generated using a vaping machine rather than a human user. The machine produced vapour from different liquid formulations and injected it into a sealed chamber with a volume of 2 cubic metres \u2014 roughly comparable to a very small phone booth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Three types of liquids were tested: a basic solvent mixture of propylene glycol and vegetable glycerin (PG\/VG), the same mixture with added terpenes (aroma chemicals such as \u03b1-pinene or geraniol), and a commercial mixture described as containing terpene-like chemicals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The researchers compared \u201cfresh\u201d aerosol in clean air with \u201caged\u201d aerosol in air containing ozone. According to Sussman, there is some ambiguity in the paper about how long aerosols were left in the chamber, noting: \u201cJudging from Table S2, the aging condition involved 30 minutes, but figures 1A and 1B shows aerosols standing during two hours.\u201d<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What the study reported<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">As summarised by Sussman, the authors measured particle size and concentration under different conditions. They reported that ozone exposure increased the formation of ultra-fine particles when terpenes were present, while aerosols made only from PG\/VG were not affected in the same way.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The authors also reported that \u201caged\u201d aerosols showed a lower threshold concentration for in vitro toxicity, while noting that oxidation of terpenes in secondary organic aerosols is already known to induce oxidative stress.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Based on these findings, the paper concluded that terpenes play an important role in vape emissions and suggested measures to reduce passive exposure, including designated vaping areas and improved ventilation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Why critics say this is not \u201cpassive vaping\u201d<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sussman\u2019s main objection is that the study did not examine what bystanders are actually exposed to. <\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cThe authors have not examined environmental e-cigarette aerosols, but laboratory aerosols within an unrealistic framework disconnected with real life usage of the devices,\u201d he said.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">In everyday settings, bystanders are exposed to what a person exhales after vaping, not to freshly generated aerosol straight from a device. Sussman argues that this difference is crucial. \u201cMachine generated e-cigarette aerosol might be an appropriate proxy for inhaled (ie active) aerosol, but not for the environmental vape aerosols exhaled by users,\u201d he said.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">He points out that the human body retains much of what is inhaled. According to figures he cites, users retain \u201c94 per cent of nicotine, 92 per cent of PG, 86 per cent of VG\u201d and \u201c97 per cent of aldehydes\u201d. As a result, what is exhaled into the surrounding air is far less concentrated and chemically different from what a machine produces.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>The problem with a tiny sealed space<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Another key criticism relates to the size of the test chamber. Sussman says a 2 m\u00b3 enclosure does not represent real indoor spaces where vaping typically occurs. \u201cA small 2 m\u00b3 telephone booth enclosure is completely unrepresentative of any real indoor volume in which users of e-cigarettes would normally puff,\u201d he said.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Injecting aerosol into such a small, sealed space can create concentrations far higher than those found in homes, offices, or public venues. Sussman says this approach can lead to \u201cartificially large concentrations\u201d that may be orders of magnitude higher than in more realistic indoor environments, even a small office.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Are the flavours representative?<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sussman also questions whether the study\u2019s focus on terpenes reflects typical nicotine vapes. He notes that the strongest effects reported by the authors were linked to ozone-driven reactions involving terpene flavourings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cAnother problem is the authors&#8217; usage of terpene compounds as the only flavor chemicals,\u201d he said. While terpene-like chemicals can be present in nicotine liquids, he says they usually appear alongside many other flavour compounds. Using terpenes alone at relatively high concentrations may be more relevant to some cannabis products than to most nicotine vapes.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>A wider debate about lab realism<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sussman\u2019s critique aligns with concerns raised in other research about laboratory methods used to assess vape exposure. In <a href=\"https:\/\/reference-global.com\/article\/10.2478\/cttr-2025-0019\" rel=\"nofollow noopener\" target=\"_blank\">a 2025 review<\/a> published in Contributions to Tobacco &amp; Nicotine Research, S\u00e9bastien Soulet and Roberto A. Sussmann argued that some lab studies generate aerosols under conditions that do not reflect consumer use, potentially producing overheated, aldehyde-rich vapour that users would find unpleasant and avoid.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Taken together, these critiques do not dispute that chemical changes can occur in vape aerosols under certain conditions. Instead, they question whether experiments conducted in small sealed chambers with machine-generated aerosol can reliably inform discussions about real-world \u201cpassive vaping\u201d exposure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n<div class=\"clear-after-content\" style=\"margin-top: 20px;margin-bottom: 20px;margin-left: auto;margin-right: auto;text-align: center;\" id=\"clear-2818540911\"><a href=\"https:\/\/www.broughton-group.com\/nicotine?utm_campaign=43296353-Clearing%20the%20Air%20PPC%20Campaign%20-%202026&#038;utm_source=ppc&#038;utm_medium=Paid%20Ads\" aria-label=\"728 x 90 (2)\"><img src=\"https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2.png\" alt=\"\"  srcset=\"https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2.png 728w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-300x37.png 300w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-370x46.png 370w, https:\/\/clearingtheair.eu\/wp-content\/uploads\/2026\/04\/728-x-90-2-600x74.png 600w\" sizes=\"(max-width: 728px) 100vw, 728px\" width=\"728\" height=\"90\"  style=\"display: inline-block;\" \/><\/a><\/div>","protected":false},"excerpt":{"rendered":"<p>A recent laboratory study examining how vape emissions change over time indoors has been cited as evidence of potential risks from \u201cpassive vaping\u201d. But experts say the experimental set-up does not reflect how vaping happens in everyday environments and could overstate bystander&hellip;<\/p>\n","protected":false},"author":990002,"featured_media":32870,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[259,257],"tags":[186],"slider":[],"class_list":["post-32863","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science","category-news","tag-nicotine"],"_links":{"self":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/users\/990002"}],"replies":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/comments?post=32863"}],"version-history":[{"count":1,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32863\/revisions"}],"predecessor-version":[{"id":32877,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/32863\/revisions\/32877"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media\/32870"}],"wp:attachment":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media?parent=32863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/categories?post=32863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/tags?post=32863"},{"taxonomy":"slider","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/slider?post=32863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}