· Lunch Boxes & Food Containers
Bentgo MicroSteel Lunch Box
Stainless steel lunch box, lower PFAS concern. No coatings disclosed.
Bentgo MicroSteel is primarily stainless steel and polypropylene containers with silicone seals. No PFAS-prone coatings are known; stainless steel is inherently lower risk. Brand makes no PFAS claims.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Stainless steel with silicone gaskets
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Category baseline
food packaging is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Silicone gasket degradation
Silicone seals can harden or crack with repeated thermal cycling and dishwasher exposure over years. Degraded gaskets lose integrity and may allow food or bacteria entry, though the stainless steel itself remains safe.
Bacterial growth in seal crevices
Silicone gaskets can trap food residue and bacteria if not cleaned thoroughly. This is a maintenance issue rather than a material hazard; proper hand-washing and occasional removal of gaskets for cleaning mitigates risk.
What’s reassuring
Uncoated safe material
Bare, uncoated material (cast iron, stainless, carbon steel, or glass) with no surface treatment to contain PFAS.
Nickel leaching from stainless steel
304-grade stainless steel (typical for food contact) releases negligible nickel under normal conditions. Acidic foods or prolonged high heat could theoretically increase leaching, but no incidents are documented for this product or material class at consumer use levels.
Microplastic shedding
Stainless steel does not shed microplastics. Silicone gaskets are not known to fragment into consumer-detectable particles during normal food storage or heating.
Coating or lining leachables
This product has no reported plastic liners, epoxy coatings, or non-stick treatments that could degrade or leach chemicals. The bare stainless steel design eliminates this hazard category.
The full breakdown
What it's made of and why it matters
The Bentgo MicroSteel uses food-grade stainless steel (typically 18/8 or 304 grade) as its primary container material, which is chemically stable and does not leach metals into food under normal use. Silicone gaskets provide the seal; food-grade silicone is inert at room temperature and typical microwave heating. The absence of plastic linings, coatings, or non-stick treatments eliminates the common leaching pathways present in many lunch boxes.
The brand's record and disclosure
Contigo (owned by Thermos) has not made explicit public statements about PFAS or chemical safety policies specific to this product line, though stainless steel construction inherently avoids PFAS-prone coatings. No recalls or safety alerts have been issued for the MicroSteel line related to material leaching or contamination. The brand does not appear to pursue third-party certifications like BPA-free or California Prop 65 labeling, suggesting a minimalist regulatory approach rather than proactive transparency.
How it compares in its category
Stainless steel lunch boxes occupy a safer tier than plastic containers with unknown BPA/BPS status or aluminum boxes with protective liners of uncertain composition. They are more durable and chemically stable than glass alternatives that risk breakage, and avoid the coating degradation issues seen in enameled or ceramic-lined food storage. The trade-off is weight and cost; stainless steel products typically command higher prices than plastic equivalents.
If you buy it
Hand-wash or use standard dishwasher cycles; stainless steel tolerates both without degradation. Silicone gaskets may retain odors over time; soak with baking soda if needed, and inspect annually for cracks or hardening. The product is microwave-safe (metal can be microwaved in brief intervals without food contact risk, though handles may heat). Replace gaskets if they no longer seal or become brittle, typically after 2-3 years of daily use.
What we don’t know
- Basis
- Model estimate, 78% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- has made none
Formulations change between production runs, so check the current label. How we grade.
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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.