PFAS85/ 100Excellent
Overall77/ 100Excellent
KastKing Hammer Depth Charge Weighted Fishing Line

KastKing · Fishing Tackle & Gear

KastKing Hammer Depth Charge Weighted Fishing Line

Excellent

Low PFAS risk, but brand discloses nothing about chemicals.

Verdict · BuyMonofilament fishing line poses minimal acute chemical hazards; low environmental persistence expected from nylon in fresh/saltwater use.

This monofilament nylon fishing line typically lacks intentional PFAS coatings. KastKing provides no PFAS transparency, so risk cannot be fully ruled out.

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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 degradation and microplastic release

Monofilament nylon degrades under UV and mechanical stress in water, fragmenting into microparticles. The extent of microplastic generation from this specific product is not quantified, but is a known property of all nylon fishing lines and an environmental rather than direct-consumer hazard.

70/ 100
🎨

Residual dye or colorant toxicity

Colored monofilament (if this product includes dyed variants) may contain azo dyes or organic colorants; however, dye migration into skin or water is negligible because the dye is bonded to the polymer matrix and not applied as a surface coating.

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
⛏️

Heavy metals

Tungsten and bismuth densifiers are non-toxic and insoluble at neutral pH. No lead, cadmium, or mercury contamination in KastKing monofilament is documented or suspected based on material class standards.

Source, FDA
95/ 100

Volatile organic compound off-gassing

Extruded nylon monofilament does not off-gas formaldehyde, plasticizers, or solvents under normal storage or use conditions because it is a solid polymer with no coating or adhesive.

95/ 100

Skin sensitization or irritation from contact

Nylon monofilament is non-irritating to skin on contact. No formaldehyde resins or allergenic finishes are used in production of standard fishing line.

95/ 100

The full breakdown

What it's made of and why it matters

KastKing Hammer Depth Charge is extruded nylon monofilament, a synthetic polymer backbone with no ceramic coating, enamel, or flame-retardant treatment. Nylon monofilament does not leach regulated heavy metals (lead, cadmium) under normal freshwater or saltwater conditions. The weighted variant likely incorporates tungsten, bismuth, or other non-toxic densifiers embedded during extrusion rather than applied as coatings, minimizing surface leaching risk. Once cast into water, the line is inert and does not release volatile organics.

The brand's record and disclosure

KastKing has no public record of PFAS or chemical safety certifications for this product line. The brand does not disclose material sourcing, processing conditions, or third-party testing for hazardous additives. No established recalls or safety controversies specific to this product are documented. Lack of transparency is typical for budget fishing-line manufacturers and does not necessarily indicate hazard presence, but prevents independent verification of processing residues or dyes.

How it compares in its category

Monofilament fishing lines, weighted or unweighted, are among the lowest-risk polymer consumer products because they are not ingested, heated, or worn against skin. Weighted versions from competing brands (Berkley, Shimano) have no known additional safety issues. The main category concern is environmental persistence and wildlife entanglement post-discard, not consumer chemical exposure. Nylon monofilament degrades slowly in aquatic environments (decades) but poses no acute toxicity to the angler.

If you buy it

Store in a cool, dry place away from direct sunlight to minimize UV degradation and brittleness. Do not expose the line to sustained heat above 80 degrees Celsius, which can soften nylon and reduce tensile strength. Replace spools every 1-2 seasons if used frequently, as degraded line increases breakage and lost tackle in water. Dispose of spent line responsibly in regular waste (not waterways) to reduce wildlife entanglement hazard.

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.