Best Non-Toxic Mouthwash in 2025


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What we look for:
- Fluoride-free formulas with safer alternatives like hydroxyapatite or baking soda
- Food-grade ingredients with no artificial dyes, flavors, or sweeteners
- No sulfates, parabens, PEGs, or triclosan
- Full transparency with every ingredient clearly disclosed
Common Harmful Chemicals in Mouthwash
Chemical Name
Why it’s harmful
Formaldehyde is a colorless, flammable gas with a pungent smell that's naturally produced in small quantities in human bodies and is also known as methanal amongst other names. It's used in the production of various items such as fertilizers, paper, plywood, and urea-formaldehyde resins as well as in some foods and household products like antiseptics, medicines, and cosmetics. Exposure to formaldehyde, which can occur through breathing contaminated indoor air, tobacco smoke, or ambient urban air can lead to respiratory symptoms, irritation of the eyes, nose and throat and has been linked to lung and nasopharyngeal cancer as well as leukemia. The EPA considers formaldehyde a probable human carcinogen (Group B1) and inhaling it can cause bronchospasm and pulmonary edema. Commercially, it's sold as formalin in solutions of 37%, 44%, or 50% and long-term exposure can cause first-degree burns, skin sensitization, squamous cell nasal cancer, and chronic pulmonary obstruction.
Formaldehyde and Cancer Risk, Cleaning Products & Indoor Air Quality, No More Toxic Tub, Campaign for Safe Cosmetics: Preservatives, Campaign for Safe Cosmetics: Formaldehyde And Formaldehyde-Releasing Preservatives, Formaldehyde may be found in cosmetic products even when unlabelled, Formaldehyde Found in Popular American Beauty Products, Hair Salons - Formaldehyde in Your Products, Formaldehyde in cosmetic products
Chlorhexidine, in its various forms, is primarily used in disinfectants, cosmetics, and pharmaceutical products in the U.S. Chlorhexidine acetate is acutely toxic when applied to the eye and can cause skin reactions, with some instances resulting in severe reactions such as anaphylactic shock. It can also cause discoloration of teeth and damage to the knees. Occupational exposure can lead to asthma in health care workers. Animal studies have shown ocular irritation in rabbits, and while there are mixed results in bacterial mutagenic studies, no carcinogenic effects were noted in long-term studies.
Cocamidopropyl betaine is a surfactant commonly found in personal care products like shampoos and body washes. However, it has been linked to skin irritation, allergic contact dermatitis, and potential reactions caused by impurities like 3-dimethylaminopropylamine. This ingredient may also contribute to skin sensitivity and has raised concerns about its environmental impact.
Chlorine dioxide is a yellow-brown gas with a pungent odor. It has versatile uses encompassing bleaching of different materials, purification of water, and manufacturing of chloride salts, among others. It's effective in controlling microorganisms at low concentrations. Human exposure can cause symptoms such as eye, nose, and throat irritation, coughing, wheezing, and in severe cases, bronchitis and pulmonary edema. Prolonged exposure has even been linked with occupational asthma and other respiratory disorders. Effects of exposure may extend to unborn children, with associations found between a pregnant woman's exposure to chlorine dioxide-treated water and prematurity or smaller cranial circumferences in newborns. Animal studies indicate that chlorine dioxide is very toxic, especially through inhalation causing respiratory distress,and oral consumption leading to death at certain doses. It was found to increase water genotoxicity and result in abnormalities in eco-toxicity studies.
Butylparaben, a chemical used in various products, has been shown to cause skin irritation in humans and potential sensitization in dermatitis patients. Animal studies indicate that it has low to moderate oral toxicity and can cause damage to the liver, spleen, and thymus. It can also lead to cell proliferation in rats' stomachs, though it was not found to be carcinogenic or mutagenic. However, it may negatively impact sperm viability and activity, as demonstrated in different in vitro and in vivo studies. Lastly, it proposed weaker aquatic toxicity compared to parabens with longer alkyl chains, but still showed estrogenic effects in certain fish species.
Ethylparaben is a chemical used as a preservative in various products including pharmaceuticals, cosmetics, and adhesives. It exhibits low toxicity in humans and animals, but can cause skin irritation, particularly when applied to damaged skin, and may worsen pre-existing skin conditions. Despite causing cell proliferation in rats' forestomachs and chromosomal aberrations in a hamster ovary cell test, it has shown no evidence of causing cancer. However, it was found to be toxic to fetuses at doses toxic to the mother, though it did not cause malformations (nonteratogenic). Interestingly, while it impacted sperm viability in lab conditions, it showed no negative effects on mouse sperm in actuality.
Campaign For Safe Cosmetics: Parabens, Product Profile: Hand Sanitizer, Parabens At A Glance, What to Know About Parabens, The effects of ethylparaben and propylparaben on the development and fecundity of Drosophila melanogaster, Ethylparaben, Amended Safety Assessment of Parabens as Used in Cosmetics, WHAT ARE PARABENS: CHEMICAL FREE LIVING, Biomonitoring Summary
Methylparaben is an antimicrobial preservative used in food, drugs, and cosmetics. Some individuals can develop contact dermatitis on skin exposure, and allergic reactions have been reported on ingestion, though the evidence is not conclusive. Data from animal studies suggest that methylparaben is practically non-toxic and non-irritating in normal skin conditions, with high thresholds for observed adverse effects. However, it showed chromosome aberrations in a cell assay and variable results in different uterotrophic assays. An ecotoxicity study found changes in the expression of certain genes at specific concentrations in male medaka, a type of fish.
Propylparaben is a stable, non-volatile compound utilized as an antimicrobial preservative in food, drugs, and cosmetics. Human exposure can cause sensitization especially if applied to damaged skin and may cause contact sensitivity with high concentrations. Extensive animal studies reveal that propylparaben is relatively non-toxic, yet it can mildly irritate skin, affect sperm counts in substantial levels, and trigger cell proliferation in the forestomach of rats. However, it is not carcinogenic, mutagenic, or clastogenic, and a significant no-observed-adverse-effect level was reported in rats. Ecotoxicity studies show that it can lead to an increase in plasma vitellogenin levels in rainbow trout and a significant decline of vitellogenin production in zebrafish at varying concentrations.
Isobutylparaben belongs to the paraben family of preservatives used in the food, pharmaceutical, and personal care product industries. Parabens mimic estrogen and have been found in breast cancer tumors in some studies. Parabens are commonly found in various personal care products and foods and have been associated with endocrine disruption, skin cancer risk, developmental and reproductive toxicity, and potential behavioral changes in offspring when exposed during gestation.
Isopropylparaben belongs to the parabens family of preservatives utilized in the food, pharmaceutical, and personal care sectors. Parabens have estrogen-mimicking properties and pose a potential risk as endocrine disruptors. Research has detected parabens in the breast cancer tumors of a significant number of studied women, raising concerns about their safety and hormonal effects.








