A law firm said Thursday that it will file a suit against a local company for selling beds that emit levels of a radioactive substance that exceed the safety standard.

Taeyul said it will take the step against Daijin Bed Co. within one or two weeks on behalf of local consumers. Some 1,500 people have joined the suit so far, and the number is expected to grow, according to the law firm.

South Korea's Nuclear Safety and Security Commission announced earlier this week that some of Daijin Bed's mattresses contained radon up to 9.3 times above the national standard.

Being exposed to radon -- a colorless, odorless, radioactive gas -- for a long period of time can lead to lung cancer, according to the American Cancer Society.

The Korea Consumer Agency said 990 complaints have been filed over the issue so far, adding it is reviewing whether to launch a collective dispute mediation process.

Daijin Bed apologized for the incident and is in the process of recalling the problematic products with all stores it operates directly being shuttered. The company could not be immediately reached for comment.

The government has also been under fire for failing to properly monitor radiation to which citizens may be exposed in their daily lives.

"At the end of the day, it was the citizens who suffered for trusting and paying more money for products that have been certified by the government," civic groups said in a joint statement.

The latest incident is one of many cases that can occur with products embedded with the negative ion, they said, calling on the government to launch a full-fledged investigation into other products and give guidelines to the public. (Yonhap)