Internet users have been speculating about the danger those seeds could pose and sharing claims that originated in Japan.
For example, a popular Japanese tweet alleges that some of these packages contain seeds of poisonous giant hogweed; it has received nearly 4,000 likes and 3,000 retweets.
The tweet shows an image of a swollen hand, implying it was severely inflamed after touching a giant hogweed plant and describing the event as “bioterrorism.”
A popular retweet in Chinese goes on further, alleging the swelling is the result of touching the seeds, not plants.
Another tweet that translates similar claims in Japanese to English shows a series of photos of inflamed hands. It has received more than 1,400 retweets and comments.
The tweet also includes a news report from CNN Japan about seeds that were sent to the U.S. through China Post. A Facebook post in Chinese that cites this tweet was shared upwards of 600 times and widely circulated in Hong Kong.
All these claims are misleading. Touching giant hogweed seeds does not cause swelling and there is no proof that giant hogweed seeds were sent in unsolicited parcels. A type of fraud called a “brushing scam” might be the reason seeds are being sent around the world.
Giant hogweed sap is indeed harmful and can cause serious skin burns when exposed to sunlight. The plant itself is classified as “noxious weed” by the U.S. federal government, and is considered an “invasive alien” and a threat to the environment in the U.K.
However, the seeds are not immediately dangerous. Taiwan FactCheck Center has reported that touching the seeds of giant hogweed does not pose a risk of skin burn because the seeds do not contain the same hazardous sap.
The images used in the social media posts are old. They were taken from a Wikipedia page about phytophotodermatitis. While giant hogweed is indeed a possible cause of phytophotodermatitis, the images do not show the result of touching unsolicited seeds recently mailed from China.
So far no credible source has reported that giant hogweed seeds have been found in the mysterious packages shipped to the U.S. or Japan.
The U.S. Department of Agriculture has identified 14 types of plants from packages received in the country, including cabbage, lavender, mint, and rose.
Meanwhile, the Japanese Ministry of Agriculture, Forestry and Fisheries has identified onions and garlic seeds. Neither government has found giant hogweed seeds in the mail people received.
While the motives behind these peculiar packages are not yet known, the U.S. Department of Agriculture (USDA), Better Business Bureau (BBB) and the Japanese National Consumer Affairs Center have reportedly concluded that circumstances strongly indicate this could be part of a “brushing scam.”
There are a few known variations of the fraud, but in essence, a company sends consumers unsolicited orders or merchandise in bulk in order to post fake reviews, comments and ratings on online stores.
A record of a delivery to a real address is often required to post reviews, but the actual content of the package does not matter, which is the reason items with nominal values such as plant seeds are often used. (There are many articles that explain how brushing scams work, including here, here and here.)
In this recent case, people are seemingly targeted at random. Although it may appear the scam is rather harmless, it isn’t clear how the fraudsters obtained the recipients’ personal information such as phone numbers and addresses.
It is possible they got the information from a black market or hackers who illegally stole customer data from somewhere.