Buff City Soap’s core bar soaps are built on a relatively simple base of plant oils and sodium hydroxide, which puts them closer to traditional soap than to the synthetic detergent bars that dominate grocery store shelves. Whether that qualifies as “non-toxic” depends on what you mean by the term, because the U.S. has no regulated definition of “non-toxic” for personal care products. The base ingredients are genuinely mild compared to common synthetic surfactants, but the full picture gets more complicated once you factor in fragrance, essential oils, and colorants.
What the Bars Are Actually Made Of
Buff City Soap’s signature product line is a soap base made primarily from plant-derived oils and butters, including coconut oil, olive oil, and shea butter, combined with sodium hydroxide (lye). When oils react with lye, saponification occurs and the result is soap plus glycerin. There is no residual lye in a properly cured bar. This is one of the oldest and most straightforward ways to make soap, and the resulting product is chemically different from the synthetic detergent bars and body washes sold by most large brands, which rely on surfactants like sodium lauryl sulfate (SLS) or sodium laureth sulfate (SLES).
The plant oils in Buff City’s formulations do have documented skin benefits. Coconut oil, for instance, has been shown to improve skin hydration and reduce water loss through the skin in patients with mild to moderate atopic dermatitis, outperforming mineral oil in a randomized trial of pediatric patients.1PubMed Central. A Comprehensive Review of Plant-Based Cosmetic Oils (Virgin Coconut Oil, Olive Oil, Argan Oil, and Jojoba Oil): Chemical and Biological Properties and Their Cosmeceutical Applications – Section: Virgin Coconut Oil (VCO) More broadly, the ratio of fatty acids in plant oils matters for skin barrier repair. Oils higher in linoleic acid relative to oleic acid tend to support the skin barrier, while those dominated by oleic acid can actually irritate it.2PubMed. Natural Oils for Skin-Barrier Repair: Ancient Compounds Now Backed by Modern Science Coconut oil’s fatty acid profile and olive oil’s properties are both well studied, and both are common in handmade soap formulations like Buff City’s.
How Plant-Based Soap Compares to Synthetic Surfactants
One of Buff City Soap’s central marketing points is that their products are “detergent free.” This distinction is worth understanding, because it is not just branding. True soap (saponified plant oils) and synthetic detergents are chemically different cleaning agents, and laboratory research suggests they behave differently on living cells. A study comparing natural soap fatty acid salts to SLS found that the natural soap compounds were dramatically less toxic to human skin cells. In cytotoxicity testing, the natural soap salts were roughly 100-fold to 1,000-fold less toxic than SLS as measured by cell membrane damage, and skin cells exposed to the soap-derived compounds showed about 16 to 32 times better viability than those exposed to SLS.3PLOS One. Natural soap is clinically effective and less toxic and more biodegradable in aquatic organisms and human skin cells than synthetic detergents
That does not mean conventional body washes are dangerous to use. SLS concentrations in finished products are far lower than in a lab dish, and millions of people use SLS-containing products daily without obvious harm. But the comparison does help explain why some people with sensitive or eczema-prone skin report less irritation when switching to plant-based soap. The gap in cellular toxicity is wide enough to be meaningful, even if everyday use dilutes it considerably.
The Fragrance Question
If Buff City Soap’s base is relatively benign, the fragrance side of things is where the “non-toxic” label gets shakier. Buff City is known for intensely scented products with names like Margarita, Pumpkin Latte, and Beach. Those scents come from blends of essential oils and fragrance oils, and both categories carry risks that the brand’s clean-ingredient marketing tends to gloss over.
Essential oils are plant-derived, but “plant-derived” and “non-toxic” are not the same thing. Patch testing data from over 84,000 dermatology patients showed that among those tested with essential oils, the most common allergic reactions were to ylang-ylang oil (about 3% positive reactions), lemongrass oil (about 2%), jasmine absolute, sandalwood oil, and clove oil (each around 1.5%).4PubMed. Contact allergy to essential oils: current patch test results (2000-2008) from the Information Network of Departments of Dermatology (IVDK) These are not rare ingredients in artisanal soap. If you are using a heavily scented bar daily, repeated exposure to allergenic essential oil compounds is a realistic concern.
Two compounds deserve special attention: limonene and linalool. Both are extremely common in fragrance formulations and occur naturally in citrus and floral essential oils. On their own, they are considered weak skin sensitizers. But when they oxidize through exposure to air and light, they form hydroperoxide compounds that are classified as strong sensitizers. Dermatology patients frequently react to these oxidation products on patch testing.5PubMed. Exposure source for skin sensitizing hydroperoxides of limonene and linalool remains elusive: An analytical market surveillance 6Toxicological Sciences. Editor’s Highlight: Fragrance Allergens Linalool and Limonene Allylic Hydroperoxides in Skin Allergy: Mechanisms of Action Focusing on Transcription Factor Nrf2 This matters for any soap that sits on a bathroom shelf for weeks or months, exposed to humidity and warmth, because oxidation happens progressively over time. A freshly made bar and the same bar three months later can differ meaningfully in its allergenic potential.
Then there is the “fragrance oil” side, which is less transparent. Fragrance oils are synthetic blends, and under U.S. regulations, manufacturers are not required to disclose the individual chemicals that make up a mixture labeled “fragrance.”7Environmental Impact Assessment Review. Fragranced consumer products: Chemicals emitted, ingredients unlisted Buff City uses phthalate-free fragrance oils according to their own disclosures, which is a meaningful exclusion. Phthalates like diethyl phthalate (DEP), historically common in fragrance formulations, have been linked to effects on sperm quality in animal studies.8PubMed Central. Hazards of diethyl phthalate (DEP) exposure: A systematic review of animal toxicology studies But “phthalate-free” does not mean “fully disclosed.” You still cannot know every chemical in the fragrance blend, which makes a blanket “non-toxic” claim hard to verify.
Research on fragranced consumer products more broadly has found that even products marketed as “green” or “organic” can emit hazardous air pollutants, and more than two-thirds of the general population was unaware of this in survey data.9PubMed Central. Fragranced consumer products: exposures and effects from emissions Soap used in a shower produces less ambient exposure than, say, an air freshener running all day. But people who are chemically sensitive or concerned about cumulative fragrance exposure should know that plant-based soap is not automatically exempt from this issue.
Colorants and Mineral Additives
Buff City’s products often feature vivid colors, which come from a combination of micas, clays, and other mineral or lab-made colorants. Micas are the most common, and the safety profile of cosmetic-grade mica is well established. A toxicological assessment of mica samples evaluated heavy metal levels and found that all tested samples fell below internationally accepted thresholds for toxicity, with both cancer-risk and non-cancer-risk indices confirming safety for adults and children.10PubMed Central. Toxicological Safety, Antimicrobial Efficacy, and Sensory Evaluation of River Sand‐Derived Mica From Bangladesh: A Comprehensive Assessment for Cosmetic Applications
The ethical sourcing of mica is a separate conversation from toxicity, and it is worth noting that the cosmetics industry has faced criticism over mining practices in some countries. From a safety standpoint, though, cosmetic-grade mica in a wash-off product like soap poses minimal risk. Most of the colorant rinses off with the lather rather than being absorbed through the skin.
What “Non-Toxic” and “Natural” Actually Mean in Personal Care
Here is where consumer expectations and regulatory reality diverge sharply. The FDA does not define “non-toxic” for cosmetics. It does not define “natural” either. A company can call its product natural or non-toxic with no third-party verification and no standard to meet. Research into consumer behavior around “natural” claims has found that companies increasingly align their marketing with sustainability and health messaging, but these claims can be deceptive, because there is no consistent standard behind them.11Business Strategy and the Environment. Understanding consumers’ purchase intentions toward natural‐claimed products: A qualitative research in personal care products
Buff City Soap is not unusual in this regard. They are transparent about avoiding certain ingredients: no parabens, no sulfates, no animal fats, no phthalates. Those are real exclusions that differentiate them from many mass-market products. But calling the finished product “non-toxic” implies a level of safety that no regulatory body has confirmed, because no regulatory body evaluates soap brands on that criterion. The absence of specific harmful ingredients is not the same as a verified claim that every component is safe for every person in every use case. It is more accurate to say that Buff City’s ingredient philosophy avoids some well-documented problem chemicals while still using fragrance and color additives that carry their own, smaller set of risks.
What Buff City Avoids That Mass-Market Brands Do Not
To give credit where it is due, some of the chemicals Buff City excludes are worth excluding. The 1,4-dioxane issue is a useful example. This compound is classified as a probable human carcinogen and shows up as a contaminant in products made with ethoxylated surfactants like SLES. It is not an intentional ingredient; it forms as a byproduct during surfactant synthesis.12PubMed. Development of analytical method for determination of 1,4-dioxane in cleansing products Testing of cosmetic products has found 1,4-dioxane at levels up to 279 ppm in finished products, and in children’s shampoos at levels above 85 ppm, prompting calls for continued monitoring.13Journal of AOAC INTERNATIONAL. Occurrence of 1,4-Dioxane in Cosmetic Raw Materials and Finished Cosmetic Products Because Buff City does not use ethoxylated surfactants, this particular contaminant is simply not part of their supply chain. That is a genuine advantage for anyone trying to reduce their chemical exposure.
Similarly, the absence of SLS and SLES means Buff City products avoid the surfactants most strongly associated with skin irritation in sensitive individuals. Research has shown that many cleansers marketed for dry or sensitive skin still produce considerable irritation, and that irritation correlates with product pH.14PubMed. Correlation between pH and irritant effect of cleansers marketed for dry skin Traditional soap tends to be alkaline (pH 9–10), which is higher than skin’s natural pH of around 4.5–5.5. Buff City’s formulations, like all true soaps, will lean alkaline. How much that matters depends on your skin. For most people, a brief exposure during washing and a thorough rinse cause no issue. For people with compromised skin barriers or conditions like rosacea or eczema, the elevated pH could be a factor worth watching, even if the base ingredients are gentler than synthetic alternatives.
Shelf Life Without Traditional Preservatives
Buff City products skip parabens and other conventional synthetic preservatives. For solid bar soap, this is less of a concern than it might be for liquid products, because bar soap’s low moisture content and alkaline pH naturally discourage microbial growth. But Buff City also sells bath bombs, body butters, and other products with higher water content or more complex formulations, where preservation becomes more relevant.
Any cosmetic product containing water and organic compounds needs some form of protection against microbial contamination to keep users safe and to prevent the product from degrading.15PubMed Central. Cosmetics Preservation: A Review on Present Strategies Some natural preservation strategies rely on the antimicrobial properties of certain essential oils or on vitamin E (tocopherol) as an antioxidant, and Buff City appears to use a combination of these approaches. The tradeoff is that products without broad-spectrum synthetic preservatives generally have a shorter effective shelf life. If you are buying Buff City products in bulk or letting them sit for months, you are accepting a slightly higher risk of product degradation compared to a conventionally preserved formula. Storing products in a cool, dry place and using them within a reasonable timeframe reduces that risk considerably.
The Laundry Soap Angle
Buff City’s laundry soap is one of their most popular products, and the toxicity question matters differently here because the product is meant for fabric, not skin. Their laundry soap is a true soap formulation, not a synthetic detergent, which has implications for both safety and performance.
On the safety side, the absence of synthetic surfactants means you avoid the 1,4-dioxane issue entirely, and residual chemicals left on clothing after washing are different in character. Research on soap-based laundry formulations has found that fabrics washed with soap alone retained more fatty acid residue than those washed with synthetic detergent blends.16Journal of the American Oil Chemists’ Society. Soap‐based detergent formulations: X. Nature of detergent deposits Fatty acid residues from plant oils are far less concerning from a toxicological perspective than synthetic surfactant residues, though they can gradually affect how fabric feels and how well it absorbs water over time. Some users report that soap-based laundry products leave a buildup in certain washing machines, particularly high-efficiency front-loaders, and periodic use of a cleaning cycle or vinegar rinse can help manage this.
Performance-wise, true soap laundry products work differently in hard water. Soap reacts with calcium and magnesium ions in hard water to form soap scum, which reduces cleaning effectiveness and can leave a film on clothes. If you have hard water and switch to Buff City’s laundry soap, you may need to adjust your approach, whether by adding a water softener to the wash or by using warmer water temperatures.
How Soap Affects Your Skin’s Microbial Community
An emerging area of research that neither Buff City nor most soap brands address in their marketing is the effect of washing on the skin microbiome. Your skin hosts a complex community of bacteria, fungi, and other microorganisms that play a role in immune defense and skin health. Using any personal hygiene product can alter the skin’s lipid film and affect microbial diversity.17PubMed Central. The dynamic relationship between skin microbiomes and personal care products: A comprehensive review
Research specifically on hand washing with soap and water showed measurable drops in bacterial diversity after washing. The number of distinct bacterial variants on the hand fell from an average of about 166 before washing to about 95 afterward, and the relative abundance of key bacterial groups like Streptococcus and Staphylococcus decreased as well.18JEADV Clinical Practice. The impact of alcohol‐based hand sanitiser and hand washing with soap and water on bacterial skin microbiota composition This is not unique to Buff City; any soap does this. The microbial community rebounds over a matter of hours. But there is emerging evidence that how you wash and what you wash with can shape the microbiome’s long-term resilience. Studies on mild, properly formulated cleansing bars have shown that they can preserve microbiome diversity and may even strengthen the network properties of skin microbial communities, which researchers associate with healthier skin.19British Journal of Dermatology. Mild skin cleansers strengthen microbiome networks without affecting the skin microbiome
Whether Buff City’s bars specifically fall into the “mild enough to preserve microbiome networks” category has not been studied. The glycerin retained in handmade soap could theoretically help, since glycerin-containing bars showed favorable microbiome effects in the research cited above. But the heavy fragrance load in many Buff City products could cut the other direction, because fragrance compounds are themselves bioactive on the skin surface. For anyone actively managing a skin condition or trying to support their skin microbiome, an unscented or lightly scented bar is a safer bet than a triple-scented one, regardless of brand.
Practical Advice for Evaluating the Products
If you are considering Buff City Soap and care about ingredient safety, a few practical points are worth keeping in mind. First, always check the specific product’s ingredient list, not the brand’s general marketing. Buff City sells dozens of products, and the ingredient profile of a basic bar soap is meaningfully different from a bath bomb or a body butter. Second, if you have sensitive skin or a history of contact allergies, the fragrance is the most likely ingredient category to cause a problem, not the soap base. Requesting a sample or testing a small area of skin before committing to daily use is worth the effort. Third, store products properly. Keeping a bar in a well-drained soap dish and out of direct humidity will reduce the oxidation of fragrance compounds and extend the product’s useful life. And finally, if your household has hard water, be prepared for the laundry soap to behave differently than a synthetic detergent, and adjust expectations accordingly rather than assuming the product is defective.
Buff City Soap is a genuinely better-formulated option than many mass-market soaps and body washes in terms of avoiding specific problematic chemicals. Calling it “non-toxic” in an absolute sense overstates what anyone can prove about a fragranced, colored personal care product that has not been through independent toxicological review. The base is clean. The fragrance and color additives introduce variables that are low-risk for most people but not zero-risk for everyone.