Just Bento

I recently got an email from a Just Bento reader concerning the plastic used to make bento boxes. She was concerned, since she couldn’t read the Japanese writing on the packaging. I’m sure a lot of other readers have similar concerns, especially given recent scares reported in the media about plastic containers leaching chemicals into food and beverages. So here’s what I’ve been able to find out by digging around on various Japanese as well as English-language web sites.

The parts of plastic bento boxes that touch food from known Japanese manufacturers seem to be made of two or three types of plastic: polyethylene terephthalate (PET), polypropylene (PP), or a compound of PET and acrylonitrile butadiene styrene (ABS) called PET-A.

For example, the inexpensive bento boxes made by Nakano Co., which includes popular brands like Puti Fresh, Lube Sheep and Clickety-Clack that are sold at Daiso and similar ‘100-yen’ stores (previously), are made of PP. According to The Green Guide ( a site that is owned and operated by National Geographic), PP is a safe plastic, though it’s not very recyclable.

Higher end plastic bento boxes such as the very popular ones from Hakoya, use mostly PET or PET-A. (Hakoya also uses other plastics on parts of their boxes that aren’t in direct contact with food.) According to The Green Guide list, the main objection against PET seems to be the porous nature of the plastic, so it’s not recommended to re-use thin PET water bottles. However, from reading some Japanese reports, PET-A in particular seems to be regarded favorably as a recyclable yet food-safe plastic. In practice, I do find that my Hakoya bento boxes are easier to keep clean and of a better finish than my Lube Sheep boxes. I don’t, however, put either kind in the microwave.

So in a nutshell, any bento box from a reputable Japanese maker should be perfectly safe. Generally speaking, food safety regulations in Japan are just as strict as they are in North America or Europe.

As for other non-Japanese manufacturers, here’s what some popular manufacturers use:

• Lock & Lock food containers (I don’t know about their non-food containers): PP
• Fit & Fresh: PP
• Ikea (their 365+ line in any case): polypropylene carbonate (PP-C)
• Tupperware (their food containers): low density polyethylene (LDPE) or PP

Plastics to avoid

It might be tempting to re-use takeout containers, but again according to The Green Guide, that may not be such a good idea.

I guess than in practice, any plastic container that is labeled as being food grade, or sold for the purpose of holding food, is safe. It may not be safe to use any old plastic container for food (or to hold/wrap portions of your bento) - but that’s just common sense - isn’t it?

See also

• How to get rid of that plastic taste in bento boxes?
• Stainless steel bento boxes (my favorite non-plastic material for bento boxes)
• More articles in the Bento Boxes category