Chlorine Free Maxi Pads vs Cotton Overnight Set Period Underwear: which is safer?
Seventh Generation Chlorine Free Maxi Pads is the clear pick. Thinx Cotton Overnight Set Period Underwear carries a failing PFAS grade, and we never recommend buying a failing product.
Our pick
Seventh Generation
Chlorine Free Maxi Pads
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleFragrance allergen content
Thinx
Cotton Overnight Set Period Underwear
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
LikelyUndisclosed waterproofing agent (likely PFAS-based)
PossibleFormaldehyde resin finishes
PossibleMembrane degradation and microplastic shedding
Where these two actually differ
- We flag Fragrance allergen content on the Seventh Generation and not on the Thinx.
- We flag Undisclosed waterproofing agent (likely PFAS-based), Formaldehyde resin finishes, Membrane degradation and microplastic shedding and Allergic contact dermatitis from undisclosed additives on the Thinx and not on the Seventh Generation.
- The Seventh Generation is organic cotton, wood pulp where the Thinx is Cotton with water-resistant membrane/lining layer (composition unspecified), which is most of the difference in these two grades.
- The gap is 75 points, wide enough that this is not a close call, and the Seventh Generation is the one to buy.
- We are less certain about the Thinx grade, at 45% confidence against 78%, because it discloses less.
Both products run through the same public rubric, which covers 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 period pads, see the full ranking