Ripple is a nicotine-free, tobacco-free vaping brand that markets itself as an aromatherapy-style “diffuser” using plant extracts and essential oils instead of nicotine. Despite the wellness branding, the growing body of research on inhaled aerosols suggests that removing nicotine from the equation does not make a vape safe for your lungs. The base liquids, the essential oils, the flavorings, and even the metal heating coils all introduce hazards that have nothing to do with nicotine.
What Ripple Is and How It Differs from Traditional Vapes
Ripple devices look and function like disposable e-cigarettes. You inhale through a mouthpiece, a battery-powered coil heats a liquid, and you breathe in the resulting aerosol. The difference is what’s in the liquid. Where a standard vape pod contains nicotine dissolved in propylene glycol (PG) and vegetable glycerin (VG), Ripple replaces the nicotine with blends of botanical extracts, vitamins, and essential oils such as lavender, chamomile, or peppermint. The company positions these as calming or energizing alternatives to nicotine products, aimed at people who want the hand-to-mouth ritual of vaping without the addictive substance.
This framing has made Ripple popular among younger adults and people trying to quit nicotine. But the implicit promise behind “nicotine-free” is that the product is harmless, and the evidence does not support that conclusion. Most of the lung-related risks researchers have identified in vaping come from the carrier solvents, the flavorings, the heating process, and the device hardware, not from nicotine itself.
What Heating PG and VG Actually Produces
Propylene glycol and vegetable glycerin are the backbone of virtually every vape liquid, including nicotine-free ones like Ripple’s. Both are approved for oral consumption and are common in food and cosmetics. But heating them changes the picture. When PG and VG are aerosolized by a coil, they undergo thermal breakdown and generate toxic byproducts including formaldehyde, acetaldehyde, and other carbonyl compounds.1Toxicology Letters. Toxicity of humectants propylene glycol and vegetable glycerin in electronic nicotine delivery systems The amount of these byproducts depends on the ratio of PG to VG, the coil temperature, and how hard the device is puffed, but the key point is that they form even at relatively low temperatures.
Research has shown that formaldehyde and acetaldehyde can be generated from both glycerol and propylene glycol at temperatures below 200°C, which is well within the operating range of many disposable vapes.2PubMed Central. Low-temperature (< 200 °C) degradation of electronic nicotine delivery system liquids generates toxic aldehydes Formaldehyde is a known carcinogen; acetaldehyde is classified as a probable one. Neither has anything to do with nicotine content. A Ripple device heating PG and VG produces the same category of thermal breakdown products as a nicotine vape heating PG and VG.
The Specific Problem with Inhaling Essential Oils
The essential oils in Ripple’s formulations introduce a risk that standard nicotine vapes don’t carry. Researchers have developed nicotine-free vape liquids using essential oils from peppermint, lavender, and tangerine as potential relaxation aids, but safety data on inhaling these oils in aerosolized form is extremely limited.3Pharmaciana. Nicotine-free vape liquids containing essential oils of peppermint, lavender, and tangerine: safety and efficacy profiles The fact that an essential oil is “natural” or safe to smell from a diffuser across the room does not mean it is safe to inhale directly into your lungs as a heated aerosol.
One serious concern is lipoid pneumonia, a condition where oily or lipid-containing substances accumulate in the lungs and trigger inflammation. A case report published in 2025 described a 72-year-old man who developed progressive shortness of breath and lung consolidation that initially looked like cancer on imaging. Extensive testing eventually traced his condition to inhaling aerosolized essential oils from a commercially available breath freshening spray.4PubMed. Exogenous Lipoid Pneumonia Due to Aerosolized Essential Oils: An Unusual Source of Chronic Pneumonia Mimicking Neoplasm The oils deposited in his lungs and set off a chronic inflammatory response.
Lipoid pneumonia has also been linked to e-cigarette use more broadly. In a cluster of cases in North Carolina, five patients developed acute lipoid pneumonia after vaping. Bronchoscopy confirmed extensive lipid deposits in their lung cells, and researchers attributed the condition to aerosolized oils depositing in the small airways and blocking gas exchange.5MMWR Morbidity and Mortality Weekly Report. Outbreak of Electronic-Cigarette–Associated Acute Lipoid Pneumonia — North Carolina, July–August 2019 A separate case report found that glycerin and propylene glycol from e-cigarettes were themselves sufficient to trigger exogenous lipoid pneumonia in a patient who also had minor occupational spray exposure.6PubMed Central. Exogenous Lipoid Pneumonia Caused by E-Cigarette Use Following Exposure to Oil Spray and Waterproofing Spray: A Case Report The takeaway is that a product combining PG/VG base liquids with essential oils is stacking two separate potential triggers for this condition.
Damage to Airway Defenses Even Without Nicotine
Your lungs have a self-cleaning system. Tiny hair-like structures called cilia line your airways and beat in coordinated waves to sweep mucus, debris, and pathogens upward and out. This mucociliary clearance system is your first line of defense against respiratory infections. Nicotine-free vaping disrupts it.
A study using repeated nicotine-free aerosol exposures on human airway tissue found that cilia beating frequency dropped by roughly 19% after 24 vaping sessions and by 53% after 60 sessions. The protective barrier formed by the airway lining also deteriorated, with measurements of barrier integrity falling by about 46% after 24 sessions and by 77% after 60.7PubMed Central. Repetitive Exposure to Nicotine-Free Vaping Impairs Airway Defences and Delays Recovery The aerosols disrupted key proteins that hold airway cells together, weakening the physical seal that keeps irritants and pathogens from penetrating deeper into lung tissue.
Research specifically on unflavored PG/VG aerosols (the carrier compounds common to all e-cigarettes, including Ripple) also found reduced cilia beat frequency and actual structural defects in the cilia themselves when examined under electron microscopy.8PubMed Central. Unflavored electronic cigarette exposure induces alterations in airway ciliary structure and function The researchers concluded that exposure to all e-cigarettes, regardless of flavor or nicotine content, reduces mucociliary clearance. Interestingly, a separate study found that short-term PG/VG exposure initially increased cilia beat frequency, possibly as a stress response, before the longer-term damage set in.9PubMed Central. Propylene glycol and vegetable glycerin e-cigarette aerosols impact mucociliary function and cause cytotoxicity in human airway epithelium The early speedup doesn’t mean improvement; it appears to be part of the pathway toward the eventual breakdown of coordinated clearance.
How Vape Aerosols Interfere with Lung Surfactant
Deep inside your lungs, the tiny air sacs where oxygen enters your blood are coated with a thin film called pulmonary surfactant. This substance reduces surface tension so that the air sacs don’t collapse with each breath. E-cigarette aerosols interfere with it. Lab studies exposing lung surfactant to e-cigarette aerosol found that the surfactant lost its ability to reach the very low surface tension values it normally achieves during breathing.10PubMed Central. E-cigarette aerosol exposure of pulmonary surfactant impairs its surface tension reducing function Even the “vehicle” aerosol, meaning PG/VG without nicotine, caused this impairment.
Flavoring chemicals make the problem worse. Research has found a flavor-dependent effect on surfactant function, meaning that certain flavoring additives disrupt the surfactant more than others.11PubMed. Adverse Biophysical Impact of e-Cigarette Flavors on Pulmonary Surfactant For a product like Ripple that combines botanical flavoring agents with the standard PG/VG base, this dual impact on surfactant is relevant. Impaired surfactant means your lungs have to work harder to inflate, and over time it could contribute to breathing difficulties.
Heavy Metals from the Heating Coil
A risk that often surprises people is that the metal coil inside any vape device, including disposable ones, leaches toxic metals into the liquid and the aerosol you inhale. This is a hardware problem, not a liquid formulation problem, so it applies to Ripple just as it does to nicotine vapes.
A 2023 study found that metal concentrations in e-liquids increased after the liquid came into contact with heating coils. Different coil materials leached different metals, with some showing dramatic increases: nickel concentrations in one e-liquid rose by a factor of roughly 180,000 after coil contact, while cadmium increased 360-fold.12PubMed Central. Occurrence of metals in e-cigarette liquids: Influence of coils on metal leaching and exposure assessment Research on disposable e-cigarettes specifically found that coil elements like chromium and nickel leached into both the liquid and the aerosol, with concentrations increasing up to 1,000-fold over the device’s lifespan. Some popular disposable brands were found to contain high levels of lead, copper, and zinc, with investigators identifying lead-containing bronze components in non-heating parts of the device that were in contact with the liquid.13ACS Central Science. Elevated Toxic Element Emissions from Popular Disposable E‑Cigarettes: Sources, Life Cycle, and Health Risks
Coil resistance also plays a role. Higher-resistance coils produce finer aerosol particles that penetrate deeper into the lungs and tend to release more aluminum, lead, chromium, and nickel into the aerosol.14NAM Journal. High-resistance coils in E-cigarettes increase heavy metals leaching into aerosols to cause oxidants generation in human bronchial epithelial cells at air-liquid interface Since disposable devices like Ripple don’t let you choose or replace your coil, you’re at the mercy of whatever materials and resistance the manufacturer selected.
Why “Food-Safe” Ingredients Are Not Necessarily Inhalation-Safe
Ripple’s marketing emphasizes that its ingredients are plant-based and natural. Many consumers interpret this as meaning the ingredients have been tested and approved for the way they’re being used. They haven’t. Flavoring compounds used in food products have regulatory approval based on oral consumption, not inhalation. The concentrations in vape liquids can be more than ten thousand times higher than in food, and the route of exposure is completely different.15PubMed Central. Policy, toxicology and physicochemical considerations on the inhalation of high concentrations of food flavour
The “generally recognized as safe” (GRAS) designation that many flavoring ingredients carry was granted by panels evaluating oral intake. Those panels do not currently evaluate inhalation safety. A compound that passes harmlessly through your digestive system may irritate or damage the delicate tissue of your lungs. Terpenes like limonene, a citrus compound common in essential oils, have been shown to cause sensory irritation of the airways and mild constriction of the bronchi in animal studies at concentrations above 1,000 ppm.16PubMed Central. Effects of R-(+)- and S-(-)-limonene on the respiratory tract in mice This doesn’t mean every puff of a citrus-flavored vape is dangerous, but it illustrates the gap between food-safe and inhalation-safe that no regulatory body has formally bridged for these products.
The Health Halo Effect in “Natural” Vaping
Ripple benefits from a marketing phenomenon researchers call the “health halo effect,” where natural-sounding branding makes consumers perceive a product as less harmful than it is. This has been studied extensively in tobacco products. When cigarette ads used phrases like “tobacco and water” or combined multiple natural-sounding cues, consumers rated those cigarettes as healthier and less likely to cause disease, and they reported higher willingness to smoke them.17PubMed Central. “Tobacco and Water”: Testing the Health Halo Effect of Natural American Spirit Cigarette Ads and Its Relationship with Perceived Absolute Harm and Use Intentions
Ripple’s branding hits many of the same notes: botanical ingredients, wellness language, the absence of nicotine, and packaging that looks more like a supplement than a vape. The reduced-harm perception this generates is not grounded in clinical evidence. No long-term safety studies on Ripple or similar botanical vape products have been published. The assumption that “natural” and “nicotine-free” add up to “safe” is a marketing artifact, not a medical conclusion.
What About Respiratory Symptoms in Real-World Users?
Large-scale data specifically on Ripple users doesn’t yet exist, but studies of young adult vapers in general show clear associations between vaping and respiratory symptoms, regardless of what substance is being vaped. Nicotine-only vapers were about 75% more likely to sound wheezy and roughly 43% more likely to have a dry night cough compared to non-vapers.18PubMed Central. Association of vaping with respiratory symptoms in U.S. young adults: Nicotine, cannabis, and dual vaping These numbers reflect the effects of the whole aerosol package, not just nicotine. The wheeze and cough likely stem from the irritation caused by inhaled PG/VG, flavorings, and thermal byproducts.
The 2019 EVALI outbreak (e-cigarette or vaping product use-associated lung injury) also demonstrated that vaping-related lung damage involves cytotoxic effects and inflammation driven by inhaled chemicals broadly, not only by one specific substance.19PubMed Central. Vaping and Lung Inflammation and Injury While EVALI was most strongly linked to vitamin E acetate in illicit cannabis cartridges, the broader lesson stands: when you heat a cocktail of chemicals and breathe the aerosol directly into your lungs, the potential for inflammation and injury is real, and nicotine is only one variable among many.
Secondhand and Indoor Exposure
People sometimes use products like Ripple indoors under the assumption that because there’s no nicotine, there’s nothing harmful in the exhaled cloud. Research on indoor vaping tells a different story. While e-cigarettes don’t produce the toxic combustion products found in cigarette smoke, vaping indoors does release aerosol particles, volatile organic compounds, and ultrafine particulate matter into the surrounding air.20PubMed Central. Secondhand Exposure to Vapors From Electronic Cigarettes
Studies of indoor vaping environments found that the residue left on surfaces from e-cigarette aerosol, sometimes called thirdhand aerosol, can be comparable to or higher than residue levels left by cigarette smoking.21PubMed Central. Indoor Air Quality and Passive E-cigarette Aerosol Exposures in Vape-Shops For a nicotine-free product, the secondhand nicotine concern drops away, but the PG/VG aerosol particles, flavoring chemicals, and any thermal degradation byproducts are still being released into the room. If you’re using Ripple around children, pets, or anyone with asthma or other respiratory conditions, the exhaled aerosol is not just harmless water vapor.
What the Research Doesn’t Yet Tell Us
The honest gap in the science is this: almost all the studies cited above examined PG/VG-based aerosols broadly or standard e-cigarette products. Ripple’s specific botanical formulations have not been independently tested in published peer-reviewed research. We don’t know the exact concentrations of essential oils in their liquids, the precise temperatures their disposable devices reach, or how the combination of their particular botanical extracts and carrier solvents behaves in the lungs over months or years of daily use. The absence of specific Ripple data is itself a safety concern. You’re essentially beta-testing a product on your own lungs without clinical evidence that it’s benign.
What we can say with reasonable confidence is that no component of the Ripple experience, not the PG/VG base, not the essential oils, not the heated metal coil, not the flavoring chemicals, has been shown to be safe for repeated inhalation. Each carries documented risks that are independent of nicotine. The product may well be less harmful than a nicotine vape in terms of addiction potential. But “less addictive” and “safe for your lungs” are very different claims, and only the first one holds up.