Citizen · Water-Resistant Smart Rings & Bands
Citizen CZ Smart Interchangeable Leather Smartwatch Strap
Leather unlikely to contain fluorochemical treatment.
Leather straps are not routinely treated with PFAS. Citizen makes no disclosure but material composition suggests lower risk.
The better-graded swap
OnePlus
Pobovi Ring Oneplus - Ultra-thin Titanium Smart Ring - Rose Gold, Size
85/100 safety
Same rubric that flunked this product. The swap earned Excellent.
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Material
Leather, stainless steel hardware
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
Chromium (hexavalent) from leather tanning
Leather tanning method unknown for Citizen straps. Chrome tanning can retain trace hexavalent chromium if process control is inadequate; risk is low on intact strap but higher if leather degrades or is ingested. No specific testing or recall data available for this product.
Formaldehyde / VOCs
Leather finishes sometimes contain formaldehyde-releasing resins to improve water resistance and durability. Citizen does not disclose finishing chemistry. Dermal exposure risk is low but chronic contact with treated leather may cause sensitivity in rare cases.
Source, ATSDR ↗Azo dyes in leather coloring
If dyed leather is used (likely for colored straps), azo dyes pose theoretical skin contact risk. Restricted azo dyes are banned under REACH and OEKO-TEX but not universally enforced in all tanneries. No brand commitment to restricted dye use is published.
Bacterial or fungal growth on worn leather
Leather worn daily on skin provides warm, moist microenvironment. Poor drying after perspiration can promote odor-causing bacteria or mold. Not a direct chemical hazard but a hygiene concern; risk manageable through regular cleaning and rotation.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Nickel leaching from stainless steel hardware
Grade 304 or 316 stainless steel (typical for watch hardware) releases negligible nickel under normal wrist conditions. Citizen does not specify grade, but no recalls or complaints on record for nickel allergy triggered by their smartwatch straps.
The full breakdown
What it's made of and why it matters
This strap is leather (animal-derived protein material) paired with stainless steel hardware. Leather's hazard profile depends entirely on tanning and finishing chemicals used during production. Chrome tanning (most common, cheaper) introduces hexavalent chromium risk if poorly controlled; vegetable tanning avoids this but Citizen does not disclose their method. Stainless steel hardware is chemically inert under normal wrist-wear conditions.
The brand's record and disclosure
Citizen does not publicly disclose leather sourcing, tanning method, or chemical restrictions for watch straps. The brand has no known recalls or regulatory sanctions tied to leather strap composition. Citizen maintains general ISO compliance for watch manufacturing but does not publish transparency reports on textile/leather supply chains comparable to apparel-focused competitors. This silence is typical for watch brands but leaves end-users without verification.
How it compares in its category
Leather smartwatch straps have lower concern as wearable accessories when sourced responsibly. Synthetic rubber or silicone alternatives eliminate chromium risk but introduce microplastic shedding and off-gassing concerns. NATO-style fabric straps avoid leather chemistry but may contain formaldehyde resins or azo dyes. Citizen's leather offering is neither exceptional nor uniquely risky; it trades transparency for perceived durability.
If you buy it
Store in a cool, dry place to slow mold and bacterial growth on leather. Avoid prolonged immersion or saturation; pat dry after water exposure. Rotate straps if possible to limit continuous skin contact with the same treated material. Replace when visible cracking, discoloration, or odor develop, typically every 2-4 years depending on use. Hand-wash with mild soap if soiling occurs; avoid bleach or solvent cleaners.
What we don’t know
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Citizen has made none
Formulations change between production runs, so check the current label. How we grade.
More water-resistant smart rings & bands 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.