Is the Premise of "Harm Reduction" Shaking? Toxicity Before Heating ─ What's Happening with E-cigarette Liquids

"E-cigarettes are safe because they 'don't burn'"—this perception has been spreading worldwide. However, a recent study from Brazil highlights a danger at an earlier stage, specifically the risk hidden in **"the liquid itself before heating."** Researchers from PUC-Rio (Pontifical Catholic University of Rio de Janeiro) and FURG (Federal University of Rio Grande) analyzed illegally distributed e-liquids and demonstrated that even before heating, there is a possibility of cellular damage. InfoMoney

Damage begins "before inhalation"—what did the study observe?

The research team focused not on the aerosols (vapors) commonly discussed as "inhalation risks," but on the **unheated liquid (e-liquid)** itself. They collected products circulating illegally within Brazil, provided by users, and classified them based on label information and declared origins (Brazil, China, Europe, Paraguay, the United States, etc.).InfoMoney

In the toxicity assessment, e-liquids were exposed to yeast (Saccharomyces cerevisiae) and rat cells at varying concentrations. It was found that depending on the concentration and chemical composition, cell growth, metabolism, and health were impaired, and signs related to oxidative stress were also investigated. The key takeaway is that rather than the "origin of the product" or "local regulations," the composition and concentration of the contents determine toxicity. InfoMoney

Why is "before heating" important: Non-inhalation exposure scenarios

It's often thought that "as long as it's not heated, it's safe," but in reality, there are points of contact beyond "inhaling." For example—

• Liquid leaks from cartridges and comes into contact with the skin

• Handling causes it to stick to hands, leading to trace ingestion through meals or contact with the mouth

• Accidental ingestion by children or pets (frequent warnings overseas)

• Liquid adheres to surrounding objects, leading to indirect contact

While this study does not directly demonstrate clinical (human body) effects, it at least raises the issue that "liquid is not just a 'raw material,'" but itself can be a burden at the cellular level. InfoMoney

The contradiction within the "basic set" of e-liquids

E-liquids are primarily based on **vegetable glycerin (VG) and propylene glycol (PG)**, with various additives such as nicotine, flavorings, and coolants. Summary reports of the study also mention the potential for these additives to enhance toxicity. jornaldachapada.com.br

What is even more troublesome is that heating can create different chemical substances. Experts from the Brazilian Society of Pulmonology point out that what e-cigarettes produce is not "water vapor" but aerosols, which can contain numerous substances.Revista Pesquisa Fapesp
In other words, risk exists even before heating / different risks arise upon heating, creating a potential two-tiered threat.

"Prohibited yet spreading"—the reality in Brazil

In Brazil, electronic cigarettes (DEF: Dispositivos Eletrônicos para Fumar) have been prohibited from manufacturing, sale, import, and advertising since 2009, and the ban has been maintained in recent reviews.Serviços e Informações do Brasil

Nevertheless, an illegal market exists, and usage is prominent among younger demographics. According to Brazilian public data, the PNS 2019 reported "0.64% current use among those aged 15 and over, equating to about 1 million people," with a high percentage among those aged 15-24.Serviços e Informações do Brasil

The presence of regulations does not equate to "safety," but rather, the structure that allows circulation despite regulations amplifies quality variations and uncertainties in labeling. The significance of this study lies in its examination of the "contents of the illegal market at the cellular level."

Acknowledging the limitations of the study

This needs to be addressed calmly. According to reports, the analysis involved 15 samples, and it was not a clinical study (i.e., it did not directly measure effects on the human body).jornaldachapada.com.br

However, the presence of limitations does not render it meaningless. Instead, it functions as a preliminary screening to indicate "where to start." Indeed, researchers have expressed intentions to delve deeper into the presence of metals and biomarkers in future studies.Rádio Metrópole - Metro 1

Experts not involved in the study have also evaluated it, stating that "e-cigarettes are not harmless" and that it serves as material to dispel the misconception of "harm reduction."jornaldachapada.com.br

Reactions on social media: Surprise, skepticism, and calls for regulation

This type of news quickly spreads "interpretations" on social media. In fact, related threads have appeared on Brazilian community forums (such as Reddit's r/brasil), where the headline point of "toxicity even before heating" is being debated.Reddit

On Instagram as well, posts citing the study's content are calling for "urgency" and "collaboration between experts and government."Instagram

Reactions tend to fall into three main categories.

1. Surprise/Anxiety Type: "Toxic before inhalation?" "Is it dangerous if it leaks?"

2. Skeptical Type: "Cell experiments ≠ human effects," "Conclusions vary with conditions"

3. Regulation/Social Issue Type: "The problem is circulation despite the ban," "What about flavors targeting youth?"

While each perspective has merit, at the very least, it can be said that the topic extends beyond "smokers' preferences" to encompass distribution (illegal market), labeling, youth entry points, and health education as societal issues. Serviços e Informações do Brasil

What will be questioned in the future

Future focus areas include (1) which combinations of ingredients increase toxicity, (2) the extent to which other contaminants like metals are involved, and (3) how actual usage environments and exposure levels affect the human body.Rádio Metrópole - Metro 1

On the policy front, not only enforcement but also prevention tailored to the actual usage among youth, smoking cessation support, and measures against online advertising and dissemination will be questioned.

Brazilian authorities (Anvisa) have organized the health risks of DEF, including respiratory diseases, cardiovascular issues, exposure to toxic substances and metals, and nicotine dependence.Serviços e Informações do Brasil

The recent report of "toxicity even before heating" adds a "new entry point" to that list.