75/ 100
C
OverallD67/100
Sunstar Gum Butlerweave Floss

Sunstar GUM · Dental Floss

Sunstar Gum Butlerweave Floss

C · Moderate

Lower PFAS concern; standard dental floss without known Teflon-family coating coatings, but brand discloses nothing.

Verdict: BuyNylon monofilament floss with no established safety concerns; standard dental category product with silent but non-controversial brand record.

Sunstar GUM Butlerweave Floss is conventional nylon dental floss with no public disclosure of PFAS-related treatments. Dental floss generally carries lower PFAS risk than water-repellent coating-treated apparel or nonstick cookware.

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Material

Nylon monofilament fiber, unwaxed or wax-coated

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Category baseline

cosmetics 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

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

Butlerweave is a nylon monofilament fiber, typically either unwaxed or coated with food-grade wax (often polyethylene or candelilla). Nylon is inert in the oral environment and does not leach into saliva under normal use. The wax coating, if present, serves to glide between teeth and is not systemically absorbed; any swallowed particles are food-grade and pose no known toxicity risk.

The brand's record and disclosure

Sunstar GUM is a major Japanese oral-care manufacturer with established regulatory compliance in the US, EU, and Asia-Pacific markets. The brand makes no specific public disclosures about PFAS, heavy metals, or other non-PFAS chemical additives in floss; this is typical for the dental floss category and does not indicate a hidden problem. No product recalls, safety controversies, or reported contamination events are on record for Butlerweave floss.

How it compares in its category

Nylon monofilament floss is the dominant material in the category and is considered a safe, standard choice by dental organizations. Butlerweave competes with silk floss (biodegradable but more expensive), waxed nylon (nearly identical safety profile), and tape variants (broader surface, same material safety). No peer-reviewed evidence suggests nylon floss poses greater risk than silk or other traditional materials.

If you buy it

Use as directed; standard floss requires no special handling or temperature precautions. Replace the spool if visible fraying or dirt accumulation occurs (typically every 6-12 months with regular use). Swallowing small lengths of floss is harmless; do not reuse floss between users. Store in a dry environment to prevent wax deterioration or mold growth on the spool.

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.”

None known

Nylon fiber ingestion

Nylon is biologically inert and not absorbed by the gastrointestinal tract; swallowing small floss fragments poses no documented toxicity or obstruction risk in adults or children.

None known

Wax coating leaching

Food-grade waxes (polyethylene, candelilla, or paraffin) used in dental floss do not leach into saliva under normal oral contact. Sunstar does not publicly identify specific wax additives, but the product category is exempt from heavy scrutiny on this hazard.

None known

Dye or colorant contamination

Butlerweave floss is typically white, mint-green, or light colored; if pigmented, the dyes are food-contact compliant in regulated markets. No reports of azo dyes, heavy metals in colorants, or allergic reactions linked to this product.

Possible

Spool or packaging materials

The plastic spool housing itself may contain BPA or other endocrine-active chemicals common in commodity plastic spools; however, contact is incidental and non-oral. If sensitive to plastics, decant floss into a glass or metal container.

Possible

Microbial growth on wet spool

If the spool is stored in humid bathrooms or left wet, mold or bacterial biofilm can accumulate on the floss or spool edge. This is a handling risk, not a manufacturing defect; allow the spool to dry fully after use and store in a cool, dry place.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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 Dental Floss

Cocofloss Refill Trio

Cocofloss

Refill Trio

Coconut fiber, based floss with plant-based coating

A
B
PFASAll
A · Very low PFAS3 flags

Lower-concern dental product; natural materials and transparent PFAS stance, but no independent verification.

Risky category by default

Refillable Silk Dental Floss

Dental Lace

Refillable Silk Dental Floss

Silk floss with compostable refillable packaging

A
A
PFASAll
A · Very low PFAS2 flags

Lower concern; silk floss with credible PFAS-free positioning and third-party certification.

MADE SAFE certified

Verified PFAS-free by a third party

Plant Based/Vegan Floss Refillable Glass Container PFAS-Free (2 Spools/4-

Dental Lace

Plant Based/Vegan Floss Refillable Glass Container PFAS-Free (2 Spools/4-

Plant-based vegan floss (likely plant cellulose or silk fibers)

A
B
PFASAll
A · Very low PFAS3 flags

Lower-concern product with explicit PFAS-free claim; no third-party verification limits certainty.

Risky category by default

More dental floss 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.