Kosas Sport Chemistry AHA Serum Deodorant (Fragrance Free)
Lower concern. Aqueous cosmetic with no known PFAS-prone additives.
Kosas Sport Chemistry is a serum deodorant without waterproofing, grease-resist, or stain-guard claims. No public disclosure of PFAS; inherent ingredient profile suggests lower risk.
We flunk more products than we pass. This one earned its grade. How we grade
Material
aqueous serum base, AHA active, mineral/plant-derived ingredients
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Kosas Sport Chemistry AHA (Fragrance Free) is made of, ingredients and materials
This is an aqueous serum base (water-dominant) with alpha-hydroxy acids as the active exfoliant and mineral or plant-derived thickeners and buffers. The water-based matrix is fundamentally lower-risk than oil or silicone serums because aqueous cosmetics have fewer solubilization pathways for persistent contaminants. AHAs themselves (glycolic, lactic acid) are approved cosmetic actives with decades of safety data; the risk profile hinges on co-formulants and preservation system, not the AHA itself.
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Formaldehyde / VOCs
Aqueous cosmetics require antimicrobial preservation. Kosas does not publicly detail its preservative chemistry for this product. Formaldehyde-releasing preservatives (DMDM hydantoin, imidazolidinyl urea) are used in some serums but not independently confirmed in this product; check full ingredient list for these compounds.
Source, ATSDR ↗Skin barrier irritation (pH and AHA concentration)
AHA serums inherently carry irritation risk, not contamination risk; this is a use hazard, not a safety defect. The product's pH and AHA strength are not publicly specified. Overuse or application to compromised skin can cause redness, peeling, or transient sensitization, requiring user discipline regardless of brand purity.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
1,4-dioxane (process contaminant)
Dioxane is a known contaminant in cosmetics with ethoxylated ingredients. Kosas does not publicly disclose testing for dioxane residues, and no independent reports cite contamination in this line, but aqueous serums with certain emulsifiers remain a theoretical pathway.
Heavy metals
No recalls or test results document contamination. Kosas's stated use of mineral or plant-derived colorants theoretically lowers risk versus synthetic dyes, but the brand has not published third-party heavy metal testing (lead, cadmium, arsenic) for this serum.
Source, FDA ↗Fragrance allergens and undisclosed components
The 'fragrance-free' label eliminates this concern for this specific product, a significant advantage over fragranced AHA serums. If reformulated with fragrance in the future, this hazard would escalate.
How is this PFAS grade calculated?
The brand's record and disclosure
Kosas maintains a clean-label marketing stance and publishes ingredient lists openly; however, the brand has not publicly disclosed comprehensive testing for contaminants like formaldehyde releasers or heavy metals in pigments, nor has it filed third-party certifications (e.g., EWG Verified). No recalls or substantiated safety incidents are on record for this product line. The 'fragrance-free' claim is verifiable and removes a major source of undisclosed allergen exposure common in cosmetics.
How it compares in its category
Fragrance-free AHA serums are less common than fragranced alternatives; this positions Kosas's offering in the lower-allergen tier of the market. Most conventional AHA serums use glycerin or humectants (commonly used ingredients) but often include dimethicone (silicone) or synthetic fragrance that this product does not contain. Plant-mineral positioning is trendy but carries no inherent safety premium; safety depends on specific sourcing and microbial controls, not marketing language.
If you buy it
Start with a patch test on inner arm or behind ear for 48 hours, as AHAs can sensitize skin, especially in higher concentrations. Use only as directed (typically 2-3 times weekly for beginners); overuse may compromise skin barrier. Store in a cool, dark place and keep the lid sealed tightly; aqueous formulas are prone to bacterial or fungal colonization if exposed to moisture or heat. Discontinue if redness, burning, or persistent irritation develops beyond the first week of use.
What is not known about PFAS in this product?
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Kosas has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Kosas Sport Chemistry AHA Serum Deodorant (Fragrance Free)?
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- Fragrance allergens (natural essential oils)
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- natural mineral powders, plant-based actives, beeswax
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- Beeswax purity and contamination
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More deodorant grades
How we score, every product runs through the same public 0-100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.