Baby Ledger AIYou are standing in the import aisle, or holding a snack a relative brought back from Tokyo, and the package is covered in kanji. Your baby has a peanut allergy. Now what?
If you shop at Japanese groceries, or you get imported snacks from family, foreign-language labels are one of the easiest places for an allergen to slip past you. This guide walks through how Japanese food labels handle allergens, the exact words to look for, why imported food is a blind spot, and what to do when a label is genuinely unreadable.
How Japan labels allergens (and why it's different from the US)
Japan has a mandatory allergen labeling system, but it does not match the US "Big 9" exactly, and that mismatch is the first thing to understand.
Japan requires labeling for a set of mandatory allergens and recommends labeling for a longer list of others. As of April 2026 the mandatory set is nine items: egg, milk, wheat, buckwheat (soba), peanut, shrimp/prawn, crab, walnut, and cashew. Walnut became mandatory in 2023 (fully enforced since March 2025), and cashew was added on April 1, 2026 with a transition period running to March 2028 - which means some packages on shelves today won't show the cashew callout yet. A second, "recommended" list of 20 covers allergens like soy, sesame, almond, macadamia, pistachio, salmon, mackerel, squid, abalone, salmon roe, beef, pork, chicken, gelatin, orange, kiwi, banana, apple, peach, and yam.
Two practical takeaways for a parent:
- "Recommended" means it may not appear at all. Soy and sesame are common allergens for babies, but on a Japanese label they fall in the recommended-not-mandatory bucket, so a product can legally contain them without a clear allergen callout. Read the full ingredient list, not just any allergen summary box.
- Buckwheat (soba) is treated as a top allergen in Japan even though it is not one of the US Big 9. If buckwheat is on your child's list, Japanese labels actually flag it more reliably than US ones do.
Where the allergen information lives on the package
Japanese packaged foods usually carry the allergen information in one of two places, and often both:
- Inside the ingredient list (原材料名, "genzairyō-mei"). Allergens appear as part of the ingredients, sometimes with the allergen name in parentheses right after an ingredient, for example "マヨネーズ（卵を含む）" meaning "mayonnaise (contains egg)."
- In a separate allergen summary line, often introduced by a phrase like "アレルギー物質" (allergy substances) or "特定原材料" (specified raw materials). This is the closest thing to the US "Contains:" line.
Look for the heading 原材料名 to find the ingredient list, and scan both the list itself and any nearby summary line.
The words to look for: the 9 major allergens in Japanese
Below are the most common label forms for each of the US Big 9 allergens. Japanese labels mix three scripts - kanji (e.g. 卵), hiragana (e.g. たまご), and katakana for many imported or loanword terms (e.g. ミルク) - so an allergen can show up in more than one form on the same package.
| Allergen | Common Japanese label forms | Read as |
|---|---|---|
| Milk | 乳 / ミルク / 牛乳 | nyū / miruku / gyūnyū |
| Egg | 卵 / たまご / 玉子 | tamago |
| Peanut | 落花生 / ピーナッツ | rakkasei / pīnattsu |
| Tree nuts | ナッツ / 木の実 / くるみ (walnut) / アーモンド (almond) / カシューナッツ (cashew) | nattsu / kinomi / kurumi / āmondo / kashū-nattsu |
| Fish | 魚 / 鮭 (salmon) / さば (mackerel) | sakana / sake / saba |
| Shellfish | 甲殻類 / えび (shrimp) / かに (crab) | kōkakurui / ebi / kani |
| Wheat | 小麦 | komugi |
| Soy | 大豆 | daizu |
| Sesame | ごま / 胡麻 | goma |
A few notes that matter at the shelf:
- Peanut vs. tree nut. 落花生 (rakkasei) is the formal word for peanut; ピーナッツ (pīnattsu) is the everyday loanword. Both mean peanut. Tree nuts are usually named individually (walnut, almond, cashew) rather than grouped, so know the specific nut on your child's list.
- Milk hides in loanwords. Beyond 乳 and 牛乳, watch for バター (butter), チーズ (cheese), and 生クリーム (fresh cream).
- Soy is everywhere. 大豆 (soy) and 醤油 (shōyu, soy sauce) appear in a huge share of Japanese products, including ones you would not expect.
"May contain" vs. "contains" on Japanese labels
Japanese labels distinguish between an ingredient that is actually in the product and a possible cross-contact from shared equipment, similar to US "may contain" wording.
- Definite presence reads like "○○を含む" ("contains ○○").
- Possible cross-contact reads like "○○を使用した設備で製造しています" ("manufactured on equipment that also processes ○○") or "○○が混入する可能性があります" ("may contain traces of ○○").
For a baby with a confirmed severe allergy, treat a precautionary "manufactured on shared equipment" line as a real signal, not fine print. When you are unsure how severe the risk is, that is a conversation for your allergist.
Why imported food is an allergen blind spot
Imported and specialty products are exactly where barcode allergen apps and crowd-sourced food databases are weakest. A product sold only in Japan, or in a single Asian grocery, often has no entry at all in the big open product databases that most scanner apps rely on.
The dangerous part is what happens next. When a scanner looks up a product and finds nothing, the naive behavior is to return "no allergens found" - which reads like "safe" even though it really means "no data." A blank record is not the same as a clean record. For a multicultural household that shops imported groceries, that gap is not an edge case; it is a weekly reality.
The right mental model: no data is a reason to read more carefully, not a green light. If you scan or search a product and the result is suspiciously empty, fall back to reading the label by eye, and when you can't read it, treat it as unverified.
What to do when the label is genuinely unreadable
Sometimes there is no English, the print is tiny, or the ingredient list is worn off. A practical sequence:
- Find the ingredient heading (原材料名) and the allergen summary line and scan for the characters in the table above. Even matching one kanji like 卵 (egg) or 小麦 (wheat) can be enough to make a decision.
- Use your phone camera's live translation (the built-in translate feature in Google Lens or your phone's camera app) to convert the panel to English. Translation can be imperfect on stylized packaging, so use it as a clue, not the final word.
- Cross-reference the brand and product online. Many Japanese manufacturers publish full ingredient and allergen information on their websites.
- When in doubt, don't feed it. If you cannot confirm a product is free of your child's allergens, the safe default is to skip it. An unread label is an unknown, and unknown is not safe.
A real example: a Japanese import the database couldn't read
To make this concrete: a barcode scan of "Gyomu Super Japan - Peanut Butter Creamy," a Japanese import, returned zero ingredient data from the open product database. Instead of reporting "no allergens found," the AllerSee scanner read the Japanese product name, recognized peanut, and flagged it against a profile where peanut was listed - prompting a "do not feed" check rather than a silent pass. In that specific scan, the product name carried "peanut" in readable text, so the name-recognition step produced a flag. Not every imported product will have an equally readable product name; false negatives remain possible. The point of the demo is the design philosophy (an empty record is a reason to look harder, not a green light) rather than a claim that the scanner catches every imported allergen.
That is the whole point of treating imported food carefully: the absence of data is itself information. The product name said peanut butter, so a careful human reader would catch it too. The lesson for any parent reading a foreign label by hand is the same one a good scanner follows - when the data is thin, look harder, don't wave it through.
Frequently asked questions
Do Japanese food labels list allergens in English?
Usually not. Products made for the Japanese domestic market are labeled in Japanese, with allergens inside the ingredient list (原材料名) and sometimes in a separate allergy-substance line. Imported retail versions sometimes carry an English sticker, but you should not count on it.
Which allergens are mandatory to label in Japan?
As of April 2026, Japan's mandatory allergen list is nine items: egg, milk, wheat, buckwheat, peanut, shrimp/prawn, crab, walnut, and cashew (cashew is in a labeling transition period until March 2028, so some packages won't show it yet). A longer list of others (including soy and sesame) is "recommended" rather than required, so those may not be flagged separately - read the full ingredient list.
How do I say peanut on a Japanese label?
Peanut appears as 落花生 (rakkasei, the formal term) or ピーナッツ (pīnattsu, the loanword). Both mean peanut.
Is "may contain" wording reliable on imported food?
Treat precautionary wording (manufactured on shared equipment, may contain traces) as a genuine signal, especially for a confirmed severe allergy. How much risk a "shared equipment" line represents for your child is a question for your allergist, not an app.
What should I do if I can't read the label at all?
Look for the key allergen characters, try your phone's camera translation, check the manufacturer's website, and if you still can't confirm it is free of your child's allergens, don't feed it. An unread label is an unverified label.