Roz Salt Scalp Scrub vs No.4 BOND MAINTENANCE 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
Olaplex
No.4 BOND MAINTENANCE SHAMPOO
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
Possible1,4-dioxane (rinse-off cosmetic contaminant)
PossibleFormaldehyde releasers (preservative antimicrobials)
PossibleFragrance allergens (undisclosed constituents)
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 Olaplex.
- We flag 1,4-dioxane (rinse-off cosmetic contaminant), Formaldehyde releasers (preservative antimicrobials), Fragrance allergens (undisclosed constituents) and Polymer buildup and scalp irritation with infrequent rinsing on the Olaplex and not on the Credo Beauty.
- The Credo Beauty is salt crystals, mineral-based scrub where the Olaplex is Aqueous surfactant blend, conditioning polymers, water, 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