2023 - Broad SREM Market Surveillance

The 2023 Broad Market Surveillance Study has been recently updated as of March 2023 and is embedded below, or you can view the direct data set here. The objective of this study is to monitor the online sale of Spherical Rare Earth Magnets (SREMs) with a diameter size ranging from 3mm to 32mm, and are being shipped to the US. The purpose of this research is to track implementation of voluntary standards and the effectiveness of CPSC enforcement in addition to providing insights into the cogency of the 2022 adult magnet ban which aimed to reduce ingestion injuries. 

The minimum confirmed diameter size for high powered magnets to be considered hazardous is 3mm according to a flux index of 50KG²mm² as specified in ASTM-F963 and ASTM-F3458. Additionally, 31.7mm is the maximum diameter size of a product that can be swallowed by children, according to the "small part" definition of ASTM-F963 via 16. C.FR 1501.4.


The study findings show an increase in the availability of SREMs to US consumers. In particular, the largest increase was observed in hazardous SREM listings on Amazon in March 2023 compared to one year prior. This increase in availability is likely due to the majority of American Ecommerce being conducted through Amazon. As of the March 2023 scan, it appears that Amazon has given up on any enforcement of hazardous magnet sales at least a few months prior. Furthermore, there was a year-over-year increase in SREM listings on eBay. Although eBay is generally more active in delisting them when informed, Aliexpress, the ecommerce division of Alibibaba, is one of the most proactive with policing and delisting SREMs.

None of the listings are known to be compliant with ASTM-F3458-21, except for Nanomagnetics. As magnetic spheres are generally not known for their industrial use, all listings are assumed to be non-compliant with ASTM-F3458-21 unless determined otherwise by packaging and labeling only. The spreadsheet categorizes availability as follows:

0 = No longer available
1 = Still available
2 = Discovered [Column] year 

The study recorded 601 new SREM listings in March 2023. Of the 373 found in 2022, 216 listings are still available, while 157 have been delisted since the March 2022 research effort.**


This research has some limitations, such as the manual research process which is time-consuming and sometimes ambiguous. Similar to 2022, approximately 40 person-hours were spent on the 2023 sweep. As per the nature of manual research of ever changing and sometimes ambiguous listing content, this data can only be considered a non-exhaustive list of all SREM sellers known. Additionally, there is no guarantee of listing accuracy since this project did not include purchasing samples for each listing. 

While 601 vs 373 is big year-over-year increase in quantity of listings found, there are a couple factors that had an inflating effect on 2023 listing counts:

On the other hand, one factor which likely caused a deflating effect on 2023 listing counts was that many of the easily found listings were already added the year prior.

Future plans

Future plans for this project include annual updates in March as resources allow, tracking the seller's country of origin, as well as differentiating between e-commerce sites that allow immediate shipping and suppliers that require contact for purchase. 

If you are aware of an online retailer of high powered magnets that is not on this list, help us make it more complete by emailing outreach@magnetsafety.org

2023 Magnetic Balls Listing Tracker - Public

Archived Data

2022 SREM Seller Listing Data viewable here.

** Listings counted in 2022, which were discovered in 2023 to have been erroneously qualified as SREMs, have been removed from this 2022 count. Qualified SREMs are Spherical Rare Earth Magnets that are within the size range of 3mm to 32mm in diameter that are also shipping to the US. And also are not weak magnets made of Hematite or Ferrite.