Roz Salt Scalp Scrub vs Straight Hair Shampoo: which is safer?
Roz Salt Scalp Scrub is our pick: better on PFAS and on the overall hazard picture.
Our pick
Credo Beauty
Roz Salt Scalp Scrub
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleFragrance allergens or undisclosed fragrance components
ReportedMechanical irritation from crystal size and shape
Function of Beauty
Straight Hair Shampoo
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleFragrance allergens and sensitizers
Possible1,4-dioxane (preservative byproduct)
PossibleEye and mucous membrane irritation from surfactants
Where these two actually differ
- We flag Fragrance allergens or undisclosed fragrance components and Mechanical irritation from crystal size and shape on the Credo Beauty and not on the Function of Beauty.
- We flag Fragrance allergens and sensitizers, 1,4-dioxane (preservative byproduct) and Eye and mucous membrane irritation from surfactants on the Function of Beauty and not on the Credo Beauty.
- The Credo Beauty is salt crystals, mineral-based scrub where the Function of Beauty is aqueous shampoo formulation; no protective coating or DWR treatment typical, 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 Credo Beauty is the one to buy.
Both products run through the same public rubric: 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 shampoo: see the full ranking