40/ 100
F
OverallF28/100
Ninja Sip Perfect Travel Mug

Ninja · Insulated Travel Mugs

Ninja Sip Perfect Travel Mug

F · High PFAS

Stainless steel core is lower concern, but seal coating raises questions.

Verdict: SkipStainless steel core is safe; leak-proof seal coating composition unclear and undisclosed by Ninja, warranting cautious use and monitoring.

Ninja's travel mug uses stainless steel, a safe base material. The waterproof seal coating is not disclosed, creating moderate uncertainty about PFAS presence in the gasket or lid treatment.

The safe swap

Corkcicle Coffee Mug

Corkcicle

Corkcicle Coffee Mug

100/100 safety

A

Still want this one anyway? Check the price on Amazon. We’d swap it.

Material

Stainless steel with leak-proof seal coating

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Waterproof / stain-resistant treatment

water-repellent coating treatments have historically used PFAS.

Hurts the grade

Category baseline

other 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

The full breakdown

What it's made of and why it matters

This mug uses a stainless steel interior and exterior, which is chemically stable and does not leach metals into beverages under normal use. The critical unknown is the leak-proof seal coating, which Ninja has not publicly specified. Seal coatings on travel mugs often contain polymer or elastomer compounds that may include fluorinated compounds (raising PFAS concerns) or other chemical treatments. Without material disclosure, the safety profile of the seal itself cannot be fully assessed.

The brand's record and disclosure

Ninja has not publicly committed to PFAS-free manufacturing or provided detailed material safety data for this product line. The brand does not appear in major PFAS accountability initiatives or certifications (such as ZDHC or bluesign). Ninja's silence on seal coating composition is typical of consumer brands but limits independent verification of safety. No product recalls related to chemical leaching have been documented for this specific mug model.

How it compares in its category

Travel mugs range widely in seal technology: some use simple rubber gaskets (lower chemical concern), while others use proprietary polymer coatings that may contain PFAS-based water repellents. Stainless steel is considered safer than plastic or ceramic for the main vessel. Compared to known PFAS-heavy brands, Ninja's lack of disclosure falls in the middle; many mainstream brands are equally opaque about seal coatings.

If you buy it

Use for cold or warm (not boiling) beverages to avoid accelerating any potential seal degradation. Clean the seal gasket regularly and inspect for cracks, discoloration, or peeling; replace if visible wear occurs. Do not microwave or expose to extreme heat. Monitor the seal for any changes in smell or appearance over 12-24 months; most manufacturers recommend replacing seals annually on high-use items.

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.”

Possible

Leak-proof seal coating composition (unspecified)

Ninja does not publicly disclose the chemical formulation of the leak-proof seal. Many such coatings contain fluorinated polymers or water-repellent treatments that may include PFAS or similar persistent compounds. Direct contact with beverages is unlikely if the seal remains intact, but degradation over time could increase exposure risk.

Possible

Coating degradation and microplastic shedding

If the seal coating contains polymeric compounds, mechanical wear from repeated opening/closing or thermal cycling may cause flaking or particulate release into beverages. No studies specific to this model exist, but this is a general concern for coated seals in all travel mugs.

None known

Heavy metals in stainless steel (leaching)

Food-grade stainless steel is stable and does not leach nickel, chromium, or other metals into cold or warm beverages under normal conditions. No known issues reported for this product or Ninja's stainless steel cookware line.

Possible

Bacterial growth in seal cavity

The seal design creates a narrow channel where moisture can accumulate and promote bacterial or mold growth if not dried thoroughly after washing. This is a maintenance issue rather than a chemical hazard but affects safe use.

None known

Off-gassing from seal materials (VOC)

No volatile organic compound emissions have been reported for this product. Stainless steel does not off-gas; risk would only arise if the seal coating contains volatile polymers, which is not documented for Ninja mugs.

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 Insulated Travel Mugs

Corkcicle Coffee Mug

Corkcicle

Coffee Mug

Stainless steel interior, insulated walls with cork/polymer exterior

A
B
PFASAll
A · Very low PFAS3 flags

Lower concern. Stainless steel interior poses minimal PFAS risk.

Naturally PFAS-free material

THERMOS Stainless Steel King Travel Mug

Thermos

Stainless Steel King Travel Mug

Stainless steel interior and exterior, plastic lid

A
B
PFASAll
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Lower concern. Bare stainless steel has minimal PFAS risk.

Bare metal or glass, no coating at all

Thermos Icon 16 oz Stainless Steel Mug

Thermos

Icon 16 oz Stainless Steel Mug

stainless steel, no stated interior coating

A
B
PFASAll
A · Very low PFAS2 flags

Lower concern. Bare stainless steel has minimal PFAS risk.

Bare metal or glass, no coating at all

More insulated travel mugs 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.