26 September 2023

False: Factory identifier code ‘K’ does not indicate Fukushima-made food products

The letter codes are assigned arbitrarily by manufacturers. One way to tell the location of the manufacturing factory is to consult the Japanese Consumer Affairs Agency database.


Concerns over the safety of imported Japanese food have become a topic of discussion in Japan’s neighboring countries after the Tokyo Electric Power Company, the operator of the Fukushima Daiichi Nuclear Power Station, updated the controversial nuclear wastewater discharge plan earlier this month.

One particular text message in Chinese claiming that there is a way to tell food items made in Fukushima has been spreading through social media, web forums and instant messaging apps since then.

A recent post with the same claim on a Hong Kong web forum, for example, was viewed over 20,000 times and have more than 200 engagements at the time of writing.

In particular, the message says if consumers see the code “K” or “Oi” next to the expiry date, the alphabet letters indicate that the product was made in a processing factory in Fukushima or the neighboring Tochigi prefecture, respectively.

However, this is not true. This claim is what fact-checkers call a zombie claim. The misinformation has been circulating on the internet since at least 2016.

These letters are self-assigned factory identifiers by food manufacturers in Japan. Therefore, the same letter can refer to factories in different prefectures.

This manufacturing site unique identification code (製造所固有記号) consists of a combination of up to 10 characters of Arabic numbers, alphabet letters and Japanese characters, that begins with the plus sign (+) and indicates the address of the manufacturing site.

Food companies can decide how to use the character combinations when they seek approval for their own identifier coding system, according to the revised Food Labeling Act that came into effect in 2016.

The manufacturers are required to disclose how their factory identification system works publicly, and Annie Lab looked at some imported Japanese food products in Hong Kong.

For example, major food manufacturer Nissin lists all of its factories in Japan and the codes assigned to each of them on its website. The two letters, “A” and “F”, that appeared in Nissin’s factory list do not match the manufacturing locations in the misleading text message.

Nissin assigned the letter “A” for products made in Toride city, Ibaraki prefecture, not Gunma prefecture, as claimed in the message. The letter “F” is assigned to a factory in Shizuoka and not in Fukuoka prefecture.

We checked some Japanese beverages in a Hong Kong supermarket and ran their unique IDs through the Japanese Consumer Affairs Agency database, which confirmed that alphabet letters are arbitrarily assigned by each brand.

The unique ID of the manufacturing site above the expiry date on an Asahi drink (right) shows it was made in Hyogo (left; Consumer Affairs Agency). The following combination, “213BCB”, further indicates the exact location of this particular factory.

The letter “T” on an Asahi alcoholic beverage means it was made in a factory in Hyogo, while “T” on a Sangaria soft drink refers to Mie.

Four bottles of Sangaria drinks with two different IDs of production sites (Source: Consumer Affairs Agency)

The manufacturing site identifier shows the location of the factory and not the origin of the raw ingredients in the products.

This recurring claim has been debunked by other fact-checking organizations in the past. MyGoPen and Taiwan Factcheck Center, as well as Hong Kong’s Kauyim media, all published stories on the same claim.

Measures taken in Hong Kong related to imported Japanese food

In mid-June, Hong Kong’s environment minister warned of toughening labelling requirements for Japanese imported food if Japan goes ahead with its discharge plan.

In 2011 the city banned all vegetables, fruits, milk, milk beverages and dried milk from Fukushima and four nearby prefectures after the nuclear accident. The rule was relaxed for imported food products from the four prefectures in 2018, but radiation certificates for live or frozen aquatic products are still required.

No sample of imported Japanese food products was found to be exceeding the limitation of radiation levels or carrying incorrect labels in Hong Kong.