It's been three months since the Chinese capital launched its origin-tracing system, "Beijing Cold-Chain" which allows customers to check the origin and nucleic acid test results of imported frozen meat and fish just by scanning a QR code with a mobile phone.

Beijing has been strengthening the system by adding more categories, including frozen dairy products, vegetables and fruits.

To know where this QR code comes from and how the origin-tracing system works requires understanding the journey of an imported product after it clears China's customs.

The first stop is customs. Normally, imported cold-chain products only need a quarantine certificate and declaration form to be cleared.

But they now need two more documents: a certificate of thorough disinfection and a negative nucleic acid test result. Anything that tests positive won't be put on the market.

Goods are then sent to a second stop, or rather, the purchasing agency, where imported goods are bought directly from a foreign company. Agents carefully examine a product's documents and upload them to a system that creates a specific QR code for that product.

The third stop is the supermarket warehouse. Goods coming in here are carefully disinfected and have their data checked, after which most are sent directly to stores. Everything is aimed at limiting the risk of cross-infection.

"We disinfect the refrigerators every two hours, especially things like the doorknobs. Our staff also get regular nucleic acid tests to make sure they are healthy, and the food is safe," a supermarket manager surnamed Ren said.

Upon arrival at the supermarket, the foods are disinfected one last time before being put on shelves, and that QR code will be attached right beside the price tag or on the product's packaging. Some supermarkets are taking things a step further.

"On every shelf, we prepare disinfectant and rubber gloves. Customers can use them to choose their preferred items without touching them directly," said Yang Haiqi, manager of retail chain giant Wumart Stores' Shuangjing branch.

Over 10,000 companies had registered on the platform by the end of 2020. This means more products to sort, more time and money to spend to ensure everything is checked and approved.

But the benefits are public health and security, which far outweigh the costs.