HydraSource Shampoo Matrix vs Roz Salt Scalp Scrub: which is safer?
Roz Salt Scalp Scrub is our pick: better on PFAS and on the overall hazard picture.
Biolage
HydraSource Shampoo Matrix
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
Possible1,4-dioxane (manufacturing contaminant)
PossibleFormaldehyde releasers (preservative system)
ReportedFragrance allergens (undisclosed components)
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 1,4-dioxane (manufacturing contaminant), Formaldehyde releasers (preservative system), Fragrance allergens (undisclosed components) and Microbial contamination if stored improperly on the Biolage 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 Biolage.
- The Biolage is aqueous shampoo formulation (water, surfactants, conditioning agents) 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