Thickening Volume Shampoo vs Roz Salt Scalp Scrub: which is safer?
Roz Salt Scalp Scrub is our pick: better on PFAS and on the overall hazard picture.
Bumble and bumble
Thickening Volume Shampoo
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleFragrance allergens (undisclosed ingredients)
Possible1,4-dioxane contamination (shampoo surfactant byproduct)
PossibleScalp irritation from sulfate surfactants
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
Where these two actually differ
- We flag Fragrance allergens (undisclosed ingredients), 1,4-dioxane contamination (shampoo surfactant byproduct) and Scalp irritation from sulfate surfactants on the Bumble and bumble and not on the Credo Beauty.
- We flag Fragrance allergens or undisclosed fragrance components and Mechanical irritation from crystal size and shape on the Credo Beauty and not on the Bumble and bumble.
- The Bumble and bumble is aqueous shampoo liquid, standard cosmetic surfactants where the Credo Beauty is salt crystals, mineral-based scrub, 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