Chemistry AHA Serum Deodorant Fragrance Free 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 Deodorant Fragrance Free

Kosas

Chemistry AHA Serum Deodorant Fragrance Free

PFAS grade

Excellent 75/100

Overall grade

Good 57/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Liquid serum with AHA active ingredients, typical cosmetic base

Confidence

72%

Possible1,4-dioxane (preservative byproduct)

ReportedSkin sensitization from AHA actives

PossibleMicrobial contamination if seal compromised

Our pick

Primally Pure Baking Soda Free Deodorant

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 1,4-dioxane (preservative byproduct), Skin sensitization from AHA actives and Microbial contamination if seal compromised 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 Liquid serum with AHA active ingredients, typical cosmetic 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