Thomastik-Infeld · Guitar Strings
Thomastik-Infeld Bronze Flat Wound ac036
Lower PFAS concern; traditional string construction unlikely to contain fluorochemicals.
Thomastik-Infeld Bronze Flat Wound strings use bronze-plated steel windings, a conventional material family with no known PFAS application. No brand PFAS disclosure exists, but the product category (wound strings) has no typical use case for Teflon-family coating or water-repellent coating coatings.
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Bronze-plated steel wound guitar strings
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
other is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
The full breakdown
What it's made of and why it matters
Thomastik-Infeld Bronze Flat Wound ac036 strings use a phosphor bronze outer wrap wound around a steel core, a classical construction dating back decades. Bronze is a copper-tin alloy chosen for tonal warmth and durability; the flat-wound design reduces finger noise and extends string life. This material composition is chemically stable under normal playing conditions and does not release volatile compounds during use. The steel core is standard across the industry and poses no inhalation or contact hazard.
The brand's record and disclosure
Thomastik-Infeld is an Austrian string manufacturer with over 100 years of history and no publicly documented safety recalls or material controversies on record. The company does not publish detailed chemical certifications or PFAS stance statements, which is typical for traditional string makers in this space. No evidence of heavy metal contamination, allergenic dyes, or flame retardants has been reported for their guitar strings. Their reputation in professional and classical music circles reflects consistent product quality.
How it compares in its category
Bronze flat-wound strings represent a lower-risk choice relative to nickel-plated alternatives, which can trigger contact dermatitis in sensitive players. Synthetic polymer-core strings introduced in recent decades sometimes contain additives or coatings not fully disclosed; bronze-core is the oldest, most transparent formulation. Thomastik-Infeld is respected for minimal processing additives compared to mass-market brands. This product sits in the premium-traditional segment rather than the budget-coated-string segment, where cost cutting sometimes correlates with undisclosed additives.
If you buy it
Store strings in a cool, dry place to prevent corrosion of the bronze wrap; humidity can accelerate oxidation over months. Wash your hands after playing to remove perspiration and dirt, which can degrade the wrap prematurely. Replace strings when they lose tone, develop visible rust spots, or fail to hold pitch reliably, typically every 3-6 months for regular players. No special heating, storage, or disposal precautions are needed; old strings can be recycled as mixed metal scrap.
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.”
Nickel contact sensitization (not present in this model)
Bronze flat-wound strings do not contain nickel in their wrap, eliminating a known allergen risk present in nickel-plated alternatives. No reported contact dermatitis linked to Thomastik-Infeld bronze strings.
Heavy metal leaching from wrap or core
Bronze (copper-tin) and steel are inert under the acidic/moist conditions of normal skin contact and saliva exposure. No documented cases of cadmium, lead, or other heavy metal release from this product category.
Corrosion byproduct inhalation
If stored in very damp conditions, bronze can develop green patina (copper carbonate), which is non-toxic but can transfer to hands. This is a storage issue, not a manufacturing hazard, and easily prevented with dry storage.
Dye or coating toxicity from wrap finish
Bronze and steel do not require synthetic dyes or chemical finishes in their production. No azo dyes, formaldehyde resins, or other coating hazards typical of fabric or cosmetics are present.
Microparticle shedding during use
Minimal bronze or steel particles may shed during normal play, but amounts are negligible and inhalation risk is effectively zero for a guitarist. No studies document adverse effects from string wear particles.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 78% 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 Guitar Strings
Martin
Retro Acoustic Guitar Strings
Phosphor bronze, stainless steel, nylon wound
Lower concern, acoustic guitar strings typically use established metals and nylon without water-repellent coating or nonstick coatings.
✓Bare metal or glass, no coating at all
Acoustic360
Ernie Ball Everlast Acoustic Guitar Strings
Phosphor bronze/stainless steel wound on steel core
Lower PFAS concern, acoustic guitar strings use standard metal materials with no known fluorochemical treatments.
✓Bare metal or glass, no coating at all
Dean Markley
Electric Guitar Strings
Steel alloy strings (nickel-plated or stainless steel core)
Lower PFAS concern, steel strings lack typical PFAS applications, but no brand disclosure exists.
✓Bare metal or glass, no coating at all
More guitar strings 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.