Chemistry AHA Serum Kosas Deodorant vs Baking Soda Free Deodorant: which is safer?
Primally Pure Baking Soda Free Deodorant is our pick, better on PFAS and on the overall hazard picture.
Kosas
Chemistry AHA Serum Kosas Deodorant
PFAS grade
Excellent 75/100
Overall grade
Good 63/100
Verdict
Buy
Hazard flags
⚑ 3
Material
water-based serum and mineral deodorant base
Confidence
72%
PossibleFragrance allergens / sensitizers in serum base
PossibleBacterial or mold growth in water-based formulation
PossibleAHA chemical irritation or photosensitivity
Our pick
Primally Pure
Baking Soda Free Deodorant
PFAS grade
Excellent 100/100
Overall grade
Excellent 96/100
Verdict
Buy
Hazard flags
⚑ 1
Material
mineral-based powder blend (arrowroot, magnesium hydroxide, mica)
Confidence
82%
PossibleSkin irritation from magnesium hydroxide alkalinity
Where these two actually differ
- We flag Fragrance allergens / sensitizers in serum base, Bacterial or mold growth in water-based formulation and AHA chemical irritation or photosensitivity on the Kosas and not on the Primally Pure.
- We flag Skin irritation from magnesium hydroxide alkalinity on the Primally Pure and not on the Kosas.
- The Kosas is water-based serum and mineral deodorant base where the Primally Pure is mineral-based powder blend (arrowroot, magnesium hydroxide, mica), which is most of the difference in these two grades.
- The gap is 25 points, wide enough that this is not a close call, and the Primally Pure is the one to buy.
Both products run through the same public rubric, which covers materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →
More deodorant, see the full ranking