PFAS85/ 100Excellent
Overall63/ 100Good
KastKing World's Premium Monofilament Fishing Line

KastKing · Fishing Tackle & Gear

KastKing World's Premium Monofilament Fishing Line

Excellent

Lower concern, monofilament nylon rarely uses PFAS.

Verdict · BuyMonofilament nylon fishing line carries minimal established chemical hazards; PFAS unlikely in this material class; standard recreational use poses low consumer risk.

This standard nylon monofilament has no known PFAS treatment. KastKing offers no PFAS disclosure, but inherent nylon composition poses lower risk than coated lines.

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We flunk more products than we pass. This one earned its grade. How we grade

Material

Monofilament nylon fishing line

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

What’s concerning

♾️

Category baseline

The starting point for this type of product, before anything specific to this product is counted.

90/ 100
♾️

No PFAS disclosure

No public statement from the brand about PFAS in this product.

85/ 100
⛏️

Nylon polymer leaching (monomers, plasticizers)

Nylon 6 and 6.6 are chemically stable in water at room temperature, but trace monomer residuals or processing agents may exist. No documented cases of toxicity from fishing-line use, and water contact is brief and incidental.

70/ 100
⚠️

UV-absorber additives

Monofilament typically includes UV stabilizers (often benzotriazole or hindered amines) to prevent photodegradation. These are bound in the polymer matrix and do not migrate during normal fishing use, but no KastKing-specific data is available.

70/ 100
🫧

Fragmentation and microplastic shedding over time

Degraded or damaged monofilament can fragment into microplastics, particularly if lost in water as litter. This is an environmental rather than direct consumer health hazard, but relevant if line is discarded improperly.

45/ 100
⚠️

Allergic sensitivity to nylon dust or residual processing chemicals

Individuals with synthetic polymer or dust sensitivities may experience mild skin irritation from prolonged handling. No systemic toxicity is expected from normal recreational use.

70/ 100

What’s reassuring

Base material not linked to PFAS

The main material recorded for this product is not one associated with PFAS.

100/ 100
🧠

Lead

Monofilament fishing line typically uses azo dyes or organic colorants; no public reports of heavy metal contamination in KastKing products. Skin contact during fishing is not a primary exposure route.

Source, ATSDR
95/ 100

The full breakdown

What it's made of and why it matters

KastKing Premium Monofilament is extruded nylon (typically nylon 6 or nylon 6.6), a synthetic polymer spun into a single continuous filament. This material is chemically stable under normal fishing conditions and does not leach into water or skin contact during use. Unlike some coated lines or braids, monofilament has minimal additives beyond colorants and UV absorbers, which reduces the surface area for chemical migration.

The brand's record and disclosure

KastKing (owned by Eposeidon) is a fishing-gear manufacturer with no documented safety recalls, chemical disclosures, or third-party certifications for this product line. The brand maintains silence on PFAS and material sourcing details, which is typical for fishing-line manufacturers but limits independent verification. No credible reports of contamination or chemical injuries linked to their monofilament products are on public record.

How it compares in its category

Monofilament nylon is the baseline standard for recreational fishing line and carries fewer chemical concerns than fluorocarbon lines (which may contain fluorine-based compounds) or heavily treated braids. KastKing's pricing and market presence suggest standard nylon extrusion rather than exotic additives, placing it in the lower-hazard tier of the category. No independent testing data exists to separate this brand from generic monofilament competitors.

If you buy it

Store in a cool, dry place away from direct sunlight to prevent UV degradation, which can weaken the line but does not generate hazardous byproducts. Replace line annually or when discoloration, brittleness, or knot failure appears, as degraded nylon may fragment during use. Wash hands after extended contact if skin irritation occurs (rare, but nylon dust or dyes could trigger sensitivity in predisposed individuals). Dispose of spent line as regular plastic waste or through fishing-specific recycling programs to reduce environmental persistence.

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
KastKing has made none

Formulations change between production runs, so check the current label. How we grade.

More fishing tackle & gear 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.