40/ 100
F
OverallF28/100
Xiaomi Smart Band 9

Xiaomi · Waterproof Smartwatches & Fitness Trackers

Xiaomi Smart Band 9

F · High PFAS

Waterproof wearables may use PFAS; Xiaomi silent on specifics.

Verdict: SkipSilicone band and stainless steel construction are low-toxicity; PFAS in waterproof coating unconfirmed but plausible; Xiaomi's silence on materials is the main concern.

Xiaomi Smart Band 9 contains a waterproof coating but the brand discloses no PFAS information. Waterproof wearables commonly use PFAS-based treatments; no third-party verification available.

The safe swap

Swatch Chrono 42 Quartz Watch

Swatch

Swatch Chrono 42 Quartz Watch

85/100 safety

B

Same rubric that flunked this product. The swap earned its B.

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

Material

Silicone band with stainless steel case, waterproof 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

The full breakdown

What it's made of and why it matters

The Xiaomi Smart Band 9 uses a silicone elastomer band paired with a stainless steel case and unspecified waterproof coating. Silicone is chemically inert and non-toxic at body temperature; stainless steel (typically 304 or 316 grade) does not leach under normal wear. The waterproof treatment applied to the band or seals is the material wild card: manufacturers typically use fluorochemical coatings (PFAS-based) or polyurethane-based water repellents, and Xiaomi has not disclosed which.

The brand's record and disclosure

Xiaomi has not published material safety data sheets, PFAS policies, or third-party certification for the Band 9. The company does not appear on public PFAS-free commitment lists. Xiaomi's general transparency on consumer health and chemical use lags behind leaders like Patagonia or Apple, though no major recalls or chemical controversies have been documented for wearables specifically. For a device worn directly on skin, this silence is a notable gap.

How it compares in its category

Among fitness trackers and smartwatch bands, Xiaomi's use of silicone and stainless steel mirrors the industry norm (Fitbit, Garmin, and Apple do the same). However, competitors like Apple publish more detailed material sourcing and have committed to phasing PFAS out of product coatings by 2025. Xiaomi's Band 9 is mid-market in safety transparency; it is not worse than generic Chinese brands but lags premium Western alternatives.

If you buy it

Wear time is low-risk: silicone does not off-gas at skin temperature, and the closed waterproof design limits direct chemical contact. Avoid prolonged contact with harsh detergents or solvents, which can degrade the waterproof coating. If the band shows cracking, peeling, or discoloration after 1-2 years, replacement is advisable to maintain the seal integrity. Wash regularly with plain water and mild soap; do not submerge in very hot water.

Beyond PFAS: other things we checked

Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”

Possible

Waterproof coating composition (PFAS likelihood)

Xiaomi has not disclosed whether the waterproof treatment uses PFAS-based fluorochemicals or alternative chemistry. Waterproof wearables often rely on PFAS; absence of a public commitment to PFAS-free coatings suggests fluorochemicals may be present.

None known

Stainless steel leaching

Grade 304 or 316 stainless steel does not leach nickel or chromium under normal skin contact at room temperature. No recalls or complaints have been documented for this product.

Possible

Silicone band degradation and additive migration

Silicone bands may contain plasticizers or UV stabilizers; heating or prolonged sunlight exposure can accelerate leaching, though skin absorption of these additives at low concentrations is limited.

None known

Skin sensitization or dermatitis

No documented allergic or irritant reactions to the Band 9 silicone or stainless steel band are on record. Individual sensitivity is rare but possible with any wearable material.

Possible

Seal integrity and bacterial/fungal growth

If the waterproof coating or seals degrade, moisture can accumulate under the band, creating an environment for microbial growth. Regular cleaning and replacement of the band when visibly degraded mitigate this risk.

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 Smartwatches & Fitness Trackers

Swatch Chrono 42 Quartz Watch

Swatch

Chrono 42 Quartz Watch

Stainless steel case, mineral/plastic crystal, standard watch components

B
C
PFASAll
B · Low PFAS2 flags

Lower concern. Standard watch materials pose minimal PFAS risk.

Brand says nothing about PFAS

Swatch SEA WASP

Swatch

SEA WASP

Plastic/resin watch case and strap

B
C
PFASAll
B · Low PFAS2 flags

Typical consumer watch, no known PFAS risk signal identified

Brand says nothing about PFAS

Swatch Neon Seppia Big Bold Chrono Quartz Watch

Swatch

Neon Seppia Big Bold Chrono Quartz Watch

Stainless steel case, plastic/resin band, mineral or acrylic crystal

B
C
PFASAll
B · Low PFAS2 flags

Lower concern. Standard watch materials typically lack intentional PFAS use.

Brand says nothing about PFAS

More waterproof smartwatches & fitness trackers 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.