Roz Salt Scalp Scrub vs No.4 Fine 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
Excellent 100/100
Overall grade
Excellent 86/100
Verdict
Buy
Hazard flags
⚑ 2
Material
salt crystals, mineral-based scrub
Confidence
82%
PossibleFragrance allergens or undisclosed fragrance components
ReportedMechanical irritation from crystal size and shape
Olaplex
No.4 Fine Bond Maintenance Shampoo
PFAS grade
Excellent 75/100
Overall grade
Good 63/100
Verdict
Buy
Hazard flags
⚑ 3
Material
aqueous liquid shampoo with surfactants
Confidence
72%
PossibleFragrance allergens (undisclosed)
Possible1,4-dioxane (potential contaminant)
PossibleEye irritation (typical product hazard)
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 Fragrance allergens (undisclosed), 1,4-dioxane (potential contaminant) and Eye irritation (typical product hazard) on the Olaplex and not on the Credo Beauty.
- The Credo Beauty is salt crystals, mineral-based scrub where the Olaplex is aqueous liquid shampoo with surfactants, 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