40/ 100
F

PFAS score

Fitbit Charge 4 Fitness Tracker

Fitbit · Waterproof Sports Watches

Fitbit Charge 4 Fitness Tracker

F · High PFAS

Insufficient transparency; waterproofing raises PFAS concerns but no public testing available.

Fitbit does not disclose PFAS use or avoidance for the Charge 4. The device's water-resistant design suggests a water-repellent coating (water-repellent coating) coating on the band and/or case, a common location for PFAS-based treatments in wearables.

The safe swap

Casio Men's Black Watch

Casio

Casio Men's Black Watch

95/100 safety

A

Still want this one anyway? Check the price on Amazon. We’d swap it.

Material

Elastomer band, stainless steel case, plastic/composite components with water-resistant coating

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Waterproof / stain-resistant treatment

water-repellent coating treatments have historically used PFAS.

Hurts the grade

Category baseline

other is a category where PFAS exposure is more common.

Hurts the grade

No PFAS disclosure

No public statement about PFAS in this product.

Hurts the grade

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 45% confidence. It is not a lab result.

No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.

The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.

Formulations and coatings change between production runs. Always check the current label before buying.

Safer alternatives in Waterproof Sports Watches

Casio Men's Black Watch

Casio

Men's Black Watch

Stainless steel case, resin band

A
B
PFASAll
A · Very low PFAS3 flags

Lower concern; standard watch materials carry minimal known PFAS risk.

Bare metal or glass, no coating at all

Seiko Men's 5 Sports Automatic Stainless Steel Watch

Seiko

Men's 5 Sports Automatic Stainless Steel Watch

Stainless steel case, acrylic crystal, leather/rubber strap

A
C
PFASAll
A · Very low PFAS4 flags

Lower PFAS concern, classic watch materials carry minimal risk, but Seiko makes no public PFAS commitments.

Bare metal or glass, no coating at all

Seiko Men's 5 Sports Automatic Watch

Seiko

Men's 5 Sports Automatic Watch

Stainless steel case, hardened crystal, synthetic rubber/elastomer strap

A
B
PFASAll
A · Very low PFAS2 flags

Lower PFAS concern; mechanical watch with standard materials, no known waterproofing coatings that typically contain PFAS.

Bare metal or glass, no coating at all

More waterproof sports watches grades

How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.