Frequently Asked Questions

 

Yumbox Bento Lunch Boxes and Thermal Food Jars

This FAQ provides answers to common questions about Yumbox leakproof Bento lunch containers, stainless steel Prêt lunch boxes, Zuppa and Cubi thermal food jars, food safety, packing tips, cleaning and care, product sizes, accessories, and more to help you find the right lunch system for school, work, or travel.

What makes Yumbox different from other lunch boxes?


Yumbox products include leakproof Bento lunch boxes and stainless steel lunch containers designed for everyday use by kids and adults. The removable, divided trays help pack balanced meals with portions for a variety of foods, while the precision silicone seal and secure locking system minimize leaks and spills. 

 

Is Yumbox leakproof lunch box really leakproof?

Yes. Yumbox Bento lunch boxes use a tight silicone seal that keeps food in place and reduces the chance of leaks between compartments or outside the box when closed properly. This makes Yumbox ideal for dressing, yogurt, dips, and moist foods with thickness — though not free liquids like soup or drinks.

What is the Yumbox Prêt stainless steel lunch box?

The Yumbox Prêt is a leakproof stainless steel Bento lunch box with four compartments, designed for kids and adults. It features an 18/8 stainless steel body and a silicone sealed lid, making it a durable and BPA-free, food-safe lunch container that is also sandwich friendly.

What are Zuppa and Cubi thermal food jars?

Yumbox Zuppa and Cubi are stainless steel thermal food jars for packing hot or cold meals and soups. Zuppa has a larger capacity suitable for adults and older kids, while Cubi is a smaller ergonomic jar ideal for younger children. Both are made from high-quality, food-safe 18/8 stainless steel that keeps food warm or cold for hours and is easy to clean. 

How do I pack wet foods in my Yumbox lunch box?

To pack wet foods like yogurt, hummus, dressings, and dips:

  1. Avoid overfilling compartments.

  2. Drain excess liquid from foods like canned fruit or heavy sauces.

  3. Pack your Yumbox in an insulated lunch bag with an ice pack to keep foods cool.

  4. Close the lid firmly, ensuring all latches are securely fastened.

This helps prevent leaks between compartments.

Are Yumbox products food safe and BPA-free?

Yes. Yumbox Bento boxes, stainless steel Prêt containers, and thermal jars are all BPA-free, phthalate-free, and food-safe. Materials comply with food safety standards suitable for everyday meal packing

Is Yumbox lunch containers dishwasher safe?

The plastic inner trays Yumbox Bento boxes are top rack dishwasher safe, but hand washing is recommended for longevity of the exterior boxes with silicone seal.

Stainless steel Prêt lunch boxes and thermal jars (Zuppa, Cubi) should be hand washed only to protect the finish and insulation, do not soak.

Yumbox is tested at a temperature of 65C/149F, 110 min. cycle.

Special Care instructions for the silicone seal:

Please be sure to empty contents of Yumbox bento boxes each day, hand wash with warm soapy water and thoroughly dry your Yumbox before storing. Also, if you live in a damp or humid environment, leave Yumbox ajar, not sealed when storing to avoid trapping moisture. If you pack oily foods regularly, coat with a baking soda paste once a week overnight to avoid build-up.

Can I microwave my Yumbox or thermal food jars?

Yumbox lunch boxes and stainless steel thermal jars are not microwave safe. Materials and insulation systems are designed for cold or room-temperature foods in the lunch box, and for thermal retention in jars. To serve warm food from a Yumbox, heat it separately before packing in a thermal jar.

Do Yumbox products keep food hot or cold?

Bento lunch boxes are not insulated on their own and do not maintain temperature over long periods. Pack them in an insulated lunch bag with ice packs to help keep foods cold.

Zuppa and Cubi thermal food jars are engineered to maintain hot or cold temperatures for extended times, making them ideal for soups, pasta, stews, and leftovers.

What sizes and models does Yumbox offer?

Yumbox offers a variety of Bento boxes and lunch containers, including:

  • Original, Panino, and Tapas models (various compartment layouts)

  • Prêt stainless steel Bento box

  • Zuppa and Cubi thermal food jars

  • Snack bowls and salad bowls

Each size fits different meal needs and portion preferences. Use the Yumbox Size Guide to pick the best fit for school, work, or adult lunches.

How do I carry Yumbox?

Yumbox is compact and fits neatly in standard size lunch totes. Yumbox insulated coolers are now available in small and large sizes. Please visit our Yumbox Shop.

Are the trays interchangeable between models?

Only Yumbox Tapas trays are interchangeable between the 4 and 5 compartment trays. However, Yumbox offers exterior boxes and trays sold separately for Original, Panino, Tapas and Snack. See Mix & Match and be sure to match the tray with the correct exterior box.

Can I buy replacement parts?

Yes. Replacement trays, exterior boxes, seals, latches, and accessories are available for most models. See Mix & Match for exterior boxes and trays. Contact support at help@yumboxlunch.com for parts.

Do Yumbox lunch containers come with utensils or drink containers?

No. Utensils and drink containers are not included with Yumbox lunch boxes or thermal jars.

Where can I buy Yumbox products?

Yumbox Bento lunch boxes, stainless steel Prêt containers, Zuppa and Cubi thermal jars are available on the official Yumbox website, Amazon, and select retailers worldwide. See Buy Local page.

Do you ship internationally?

Yumbox ships directly to the United States. For international shipping, find a global retailer partner using the Buy Local page

How should I care for my Yumbox products?

Hand wash stainless steel lunch boxes and thermal jars with warm soapy water. For plastic trays and seals, hand wash or use the dishwasher’s top rack. Dry components thoroughly before storing to prevent moisture build-up

Is Yumbox food safe?

Yes. All materials are food-safe, BPA-Free, Phthalates-free and are CPSIA and FDA compliant.

I am a Retailer or Distributor and would like to learn more about Yumbox.

We would love to hear from you! Please contact us at help@yumboxlunch.com.