Monbento MB Original Bento Box
Lower concern, typical food container; brand offers no PFAS disclosure.
Monbento MB Original is a rigid plastic and stainless steel bento box with no known PFAS-related coatings. No brand PFAS claims or third-party verification available.
We flunk more products than we pass. This one earned its grade. How we grade
Material
ABS plastic and stainless steel construction
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What Monbento MB Original Bento Box is made of, ingredients and materials
The Monbento MB Original uses ABS plastic for the main compartments and lids, paired with stainless steel hinges and closures. ABS is a harder, non-leaching engineering plastic that does not contain BPA or phthalates by design, making it a lower-concern choice for food contact compared to softer plastics. The stainless steel hardware eliminates concerns about cadmium or lead in metal parts. The two materials are chemically distinct, reducing the risk of leaching from mixed material degradation.
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Microplastics
ABS can shed microparticles if the plastic becomes brittle with age or if repeatedly stressed by thermal shock. Risk is lower than with softer plastics but increases if the box is microwaved, filled with very hot liquids, or used beyond 5-7 years without replacement.
Source, EPA ↗What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
BPA & bisphenols
ABS resin does not typically contain BPA or structural bisphenols; no recalls or detections are on record for Monbento MB Original. Monbento offers no explicit certification, but material class chemistry supports low likelihood.
Source, FDA ↗Phthalates
ABS does not require phthalate plasticizers in formulation, unlike PVC or some flexible polymers. No recall history or industry reports suggest phthalate content in this product.
Source, ATSDR ↗Stainless steel leaching (nickel, chromium)
Food-grade stainless steel (typically 304 or 18/8) used in hinges and clasps poses negligible leaching risk in normal use. Monbento does not specify alloy, but no reports of nickel or chromium contact issues exist for this product line.
Coating degradation or delamination
The MB Original does not feature a separate coating on the plastic body; ABS is inherently colored or pigmented during molding. No widespread reports of paint flaking, peeling, or surface coating loss in this product.
The full breakdown
The brand's record and disclosure
Monbento is a French-based bento box specialist with a focus on reusable food containers and sustainability marketing. The brand does not publicly disclose PFAS testing or certification, and no major recalls or safety controversies are on record for the MB Original line. Transparency on chemical composition is limited; the brand does not publish third-party safety testing or BPA/BPS statements, though ABS resin suppliers typically do not add these compounds.
How it compares in its category
ABS bento boxes sit in the middle-ground of food-storage plastics, they are more durable and less chemically reactive than polycarbonate or polyvinyl chloride (PVC) alternatives, but less rigorously tested than glass or stainless steel only containers. Most reusable bento boxes on the market use similar ABS or polypropylene construction; Monbento's stainless steel hinges are a step above all-plastic competitors. Price and durability favor this product over single-use containers, though glass-lid variants offer marginally lower leaching risk.
If you buy it
Keep the box below 70C (160F) for extended storage to avoid any potential stress-induced leaching from ABS; do not microwave or fill with hot liquids immediately after opening. Inspect the lids and seals every 6 months for cracks or warping, as damaged plastic can shed particles and lose sealing integrity. Hand wash rather than dishwasher if possible, as repeated hot cycles may weaken hinges over years of use. Replace the box if the plastic becomes visibly brittle, discolored, or produces odor, which signals degradation.
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
- Monbento has made none
Formulations change between production runs, so check the current label. How we grade.
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More lunch boxes 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.