Crest · Dental Floss
Cascade Crest Fluorescent Floss, Black/Rayon
Lower PFAS concern; dental floss is rarely treated with PFAS, but Crest should clarify.
Cascade Crest Fluorescent Floss is rayon-based dental floss with no disclosed coatings or treatments. Rayon itself is not a PFAS-typical material, and dental floss rarely undergoes water-repellent coating or stain-resistant treatment.
Shop Crest on Amazon →Material
Rayon floss, no coating disclosed
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.
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
Cascade Crest Fluorescent Floss is a rayon-based dental floss, meaning the filament is cellulose derived from wood pulp. Rayon is a regenerated natural fiber with no inherent toxicity concerns in the mouth. The black dye is the only chemical additive of note; if it uses azo dyes (common in textiles), migration into saliva during use is negligible because floss contact is brief and the dye is chemically bound to the fiber. No protective coating is disclosed, which eliminates concerns about Teflon-type coating, silicone, or wax-based additives that could leach or shed.
The brand's record and disclosure
Crest (owned by Procter and Gamble) does not publicly disclose material sourcing or dye specifications for this floss product. The company has not faced recalls or safety actions on dental floss. P&G maintains general commitment to ingredient transparency but does not provide granular detail on colorant chemistry for this SKU. No third-party certifications (such as organic or eco-certifications) are claimed for this product.
How it compares in its category
Rayon floss is a mainstream choice, sitting between synthetic nylon (more durable) and silk (softer, costlier). Rayon products carry no established hazard premium versus nylon in the dental category. Fluorescent black dyes in textiles are routine and not a known concern for oral-contact products. This product is chemically simpler than waxed or coated flosses, which reduces potential for undisclosed additives.
If you buy it
Use floss as directed (once daily, brief contact time) with no special precautions. Rayon does not require heat care since dental floss is not exposed to cooking temperatures. Replace the spool once dye visibly fades or fraying begins, typically every 3-6 months depending on storage humidity. Store in a dry location to prevent mold growth on the cellulose fiber. Do not ingest floss; accidental ingestion of small amounts poses no known toxicity, but swallowing large amounts can cause intestinal obstruction.
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.”
Azo dyes (black colorant)
Black dyes in rayon textiles may use azo chemistry, which can release aromatic amines under certain conditions (acid/heat/bacterial degradation). In the oral cavity at neutral pH and body temperature, migration is not established as a risk during normal short-contact flossing. Saliva does not significantly degrade the dye bond.
Rayon fiber shedding / microfiber aspiration
Rayon fibers can fray and shed microscopic particles if floss is degraded or roughly used. Inhalation risk is minimal because floss is used in the mouth; however, if fibers are shed and swallowed in quantity, they are inert cellulose and pose no chemical hazard, though mechanical irritation is theoretically possible.
Bacterial or mold growth on stored floss
Cellulose is susceptible to microbial colonization in humid environments. If floss is stored in a damp bathroom without proper closure, bacterial or fungal growth can occur on the spool. This is a hygiene concern rather than a chemical one; regular replacement and dry storage prevent this.
Heavy metals in black pigments
Black textile dyes historically sometimes contained iron oxides or carbon black (safe) but older formulations could include cadmium or lead compounds. No recalls or safety warnings exist for Crest floss; modern dye standards in the U.S. exclude toxic heavy metals. Crest does not disclose pigment type, but regulatory compliance is assumed.
Undisclosed wax, silicone, or coating additives
Product description states no coating; however, some rayon floss is treated with mineral oil, carnauba wax, or silicone for glide. Crest does not list these. If present, they are food-grade materials with minimal oral absorption risk. Absence of disclosure is a transparency gap, not a known hazard.
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
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⚠Risky category by default
Dental Lace
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Lower concern; silk floss with credible PFAS-free positioning and third-party certification.
✓Verified PFAS-free by a third party
Dental Lace
Plant Based/Vegan Floss Refillable Glass Container PFAS-Free (2 Spools/4-
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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.