90/ 100
A
OverallC72/100
GreenPan Kyoto 12" Carbon Steel Wok

GreenPan · Woks

GreenPan Kyoto 12" Carbon Steel Wok

A · Very low PFAS

Lower PFAS concern, bare carbon steel wok, no Teflon-family coating needed.

Verdict: BuyBare carbon steel eliminates coating risks; no nonstick degradation or Teflon-type coating fume hazard; GreenPan's PFAS-free positioning aligns with material choice.

The GreenPan Kyoto 12 is uncoated carbon steel, which does not require PFAS-containing nonstick treatments. GreenPan's brand positioning emphasizes PFAS-free products. No third-party lab data or independent verification on file, but the material class itself carries minimal PFAS risk.

Brand says: “GreenPan markets this as PFAS-free; carbon steel wok with no synthetic nonstick coating.

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Material

Carbon steel, no nonstick coating

Brand disclosure

Brand claims PFAS-free

Lab data

No public lab test

Why this grade

Category baseline

cookware is a category where PFAS exposure is more common.

Hurts the grade

Brand-stated PFAS-free

The brand states the product is PFAS-free (self-declared).

Helps the grade

Safe base material

Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).

Helps the grade

The full breakdown

What it's made of and why it matters

This wok is bare carbon steel with no nonstick or ceramic coating, meaning no Teflon-family coating (Teflon-type coating) fumes, no epoxy-resin liners, and no glaze-based lead or cadmium exposure. Carbon steel is iron-carbon alloy that develops a natural seasoning layer (polymerized oil) as its only protective surface. The 12-inch size is standard for home use and heats evenly without the degradation risks that plague coated cookware.

The brand's record and disclosure

GreenPan is a Valencia-based brand that explicitly markets nonstick cookware as PFOA and PFAS-free since entering the market in 2007. However, this particular product is not nonstick cookware but rather bare carbon steel, sidestepping the entire controversy around alternative Teflon-type coating coatings (Thermolon, ceramic) that GreenPan's core line relies on. No major recalls or heavy-metal contamination reports have been published for GreenPan carbon steel woks.

How it compares in its category

Bare carbon steel woks are among the safest cookware options chemically because they eliminate coating variables entirely. Unlike nonstick woks (which may off-gas if overheated), enameled cast iron (which can chip and expose iron), or stamped steel with unclear finishes, this product requires only oil seasoning. It sits at the traditional end of the wok market, favored by professional and chemistry-conscious home cooks precisely because simplicity reduces contamination risk.

If you buy it

Season the wok thoroughly before first use with neutral oil (vegetable or grapeseed) on medium-high heat to build the protective patina; do not exceed 400-450°F during seasoning to avoid excessive smoke. Hand-wash only after each use; avoid dishwasher and prolonged soaking, which degrade seasoning. Re-season periodically if rust spots appear. The wok will last decades with proper care and carries minimal chemical leaching risk compared to coated alternatives.

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

Iron leaching at low pH

Bare carbon steel can leach iron into acidic foods (tomato, vinegar, citrus) if seasoning is thin or damaged. This is not acutely toxic but can raise dietary iron intake and may affect taste. Regular re-seasoning minimizes this risk.

Reported

Rust formation if improperly maintained

Bare carbon steel corrodes rapidly if left wet or stored in humid conditions. Rust itself is iron oxide (not acutely toxic) but creates rough texture, food sticking, and potential for metallic off-flavors. Proper drying and oil storage prevent this.

None known

Coating degradation (none present)

No ceramic, enamel, or nonstick coating means no chip-off risk, no Teflon-type coating fume hazard at high temperature, and no need for replacement. This is a primary safety advantage of bare carbon steel.

None known

Heavy metals in steel (lead/cadmium)

No published recalls or test data indicating lead or cadmium contamination in GreenPan carbon steel cookware. Modern wok steel is typically food-grade iron-carbon alloy with minimal impurities, though sourcing and manufacturing standards vary by factory.

Possible

Oil residue rancidity from seasoning buildup

Over months, thick seasoning layers can trap rancid oil if not refreshed. While rancidity is unpleasant rather than acutely toxic, it can produce off-odors and taste. Occasional light re-seasoning and proper drying prevent accumulation.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 82% 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.

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

More woks 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.