Flexifit Medium Support Sports Bra vs Reversible Seamless Sports Bra: which is safer?

Marks & Spencer Reversible Seamless Sports Bra is our pick: better on PFAS and on the overall hazard picture.

Marks & Spencer

Flexifit Medium Support Sports Bra

PFAS grade

F 20/100

Overall grade

F 0/100

Verdict

Skip

Hazard flags

⚑ 5

Material

Polyester/elastane blend with water-repellent coating treatment

Confidence

42%

LikelyFormaldehyde resins (polyester finishing)

PossibleAzo dyes and synthetic colorants

PossibleAntimony in polyester

Why this grade

Our pick

Marks & Spencer

Reversible Seamless Sports Bra

PFAS grade

D 65/100

Overall grade

F 49/100

Verdict

Skip

Hazard flags

⚑ 4

Material

Nylon blend with elastane, seamless construction

Confidence

72%

PossibleAzo dyes (colorants)

PossibleFormaldehyde resins (finishing agents)

PossibleElastane degradation and microfiber shedding

Why this grade

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 sports bras: see the full ranking