Kosas Review, Is Kosas Non-Toxic?
PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Grades are model-based, built from published ingredients, materials, certifications, brand disclosures and third-party lab results where they exist. See the rubric.
Across 7 graded products, Kosas averages Excellent (75/100). On disclosure, the brand says nothing publicly about PFAS. 7 of its products grade Good or better. Grades are model-based estimates, not lab results.
Worth buying from Kosas Good or better, safest first
Kosas
Chemistry AHA Serum Kosas Deodorant
water-based serum and mineral deodorant base
Fragrance allergens / sensitizers in serum base
No specific fragrance allergen disclosures are available for this product. Serum-based…
Bacterial or mold growth in water-based formulation
Water-based cosmetics require preservative systems to prevent microbial contamination…
AHA chemical irritation or photosensitivity
Alpha hydroxy acids are exfoliants that can cause skin sensitization, redness, and…
Low-Medium risk typical cosmetic with no flagged additives.
⚠Risky category by default
Kosas
Chemistry Deodorant (Beachy Clean)
Deodorant base (presumed mineral/plant oil)
Fragrance allergens and essential oils
Kosas Chemistry lists essential oils and fragrance components (beachy scent profile…
Bacterial or mold growth from oil degradation
Solid oil-based deodorants can develop bacterial or fungal growth if exposed to moisture…
Low-Medium risk solid deodorant typical of the category without brand assurance.
⚠Risky category by default
Kosas
Дезодорант Chemistry Aha
Standard cosmetic formulation (deodorant base)
Fragrance allergens and skin sensitization
Deodorants typically contain fragrance blends (parfum) that may include undisclosed…
1,4-dioxane as fragrance contaminant
Deodorants with fragrance systems may inadvertently contain 1,4-dioxane, a synthetic…
Skin irritation from exfoliating acids (if AHA content is high)
The 'Aha' branding suggests alpha-hydroxy acid inclusion for odor or skin benefits.…
Low-Medium risk typical deodorant without known PFAS drivers.
⚠Risky category by default
Kosas
Kosa Ayurveda - Pitta Probiotic Deodorant
Mineral powder, plant-based ingredients, baking soda, arrowroot
Baking soda skin irritation
Sodium bicarbonate (baking soda) is a known irritant for sensitive or broken skin in some…
Fragrance allergens and undisclosed fragrance chemicals
Kosa lists 'fragrance' derived from plant sources but does not itemize specific essential…
Low-Medium risk powder deodorant with no typical PFAS profile.
⚠Risky category by default
Kosas
Chemistry Deodorant - Aluminium and Baking Soda Free + BO-Fighting AHA Serum that Exfoliates Softens and Nourishes the Skin (Fragrance Free)
aqueous cream serum and powder deodorant base
AHA irritation and skin barrier disruption
This product markets an AHA serum component (likely glycolic or lactic acid). While…
Low-Medium risk liquid and powder cosmetic without PFAS-prone coatings.
⚠Risky category by default
Kosas
Kosa Ayurveda - Vata Probiotic Deodorant
Mineral powder, natural gum base, essential oils, probiotics
Talc or talc-alternative mineral content
If the mineral powder base includes talc, chronic inhalation risk exists, though modern…
Essential oil sensitization and photoallergy
Natural deodorants often contain citrus or lavender oils that can trigger contact…
Probiotic stability and contamination risk
Live or lyophilized probiotics in powder form depend on cold storage and low humidity for…
Low-Medium risk probiotic powder deodorant with no typical PFAS vectors.
⚠Risky category by default
Kosas
Kose - Desodorante Stick Deo Carat
Stick deodorant base (typically waxes, oils, starch)
Fragrance allergens (undisclosed components)
Product does not list specific fragrance ingredients; synthetic fragrance blends in…
Aluminum salts in antiperspirant active (if present)
If this product contains antiperspirant-grade aluminum compounds (e.g., aluminum…
Skin irritation from wax or oil oxidation over storage
Over time, unsaturated oils in the base may oxidize if exposed to air or UV light…
Lower PFAS concern but no public disclosure from Kose.
⚠Risky category by default
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