Two Maersk container ships suspected to be transporting hazardous furnace waste from Albania to Thailand have been barred from docking at Thai ports and are being rerouted back to Europe, according to Thai authorities.

According to the Basel Action Network (BAN), an NGO that campaigns against toxic waste exports, there are an estimated 816 tonnes on board the two ships in containers that are believed to be carrying toxic steel furnace dust collected from pollution control filters.

Reportedly, they were intended for delivery to Laem Chabang Port in Chon Buri province, Thailand. However, the Thai authorities have been working to block the shipment after being alerted by BAN.

According to BAN, there are concerns that if no action is taken, the toxic filter dust could be spread on agricultural land or otherwise dumped in Thailand. Earlier this year, a similar shipment was intercepted in China, where authorities found it contained over 8% toxic lead.

If determined to be hazardous waste under the Basel Convention—a United Nations treaty that regulates the trade of hazardous and other wastes—the containers could be confiscated and sent back to Albania.

Thailand, along with other Southeast Asian nations, has experienced a surge in waste imports from developed countries. 

The director-general of the Department of Industrial Works in Thailand, Chulaphong Thawisri, said in a Facebook post that the department is closely monitoring the transport of "red dust" from Albania with the aim "to closely monitor and suppress the transport of hazardous waste (illegal traffic), believed to be Electric Arc Furnace (EAF) dust or red dust from the steelmaking industry, totaling 816 tons (approximately 100 containers) from Albania." 

Deputy Transport Minister Manaporn Charoensri announced on August 14 that the Maersk Candor, one of the vessels in question, was last reported off the coast of South Africa on Friday, reported the Bangkok Post. The vessel was scheduled to arrive in Singapore on August 24. 

The second vessel, the Maersk Campton, was expected to reach Singapore by Thursday. The Maersk Campton, carrying 40 containers of the suspect cargo, is now slated to return to Italy, according to marine cargo tracking data from MSC Mediterranean Shipping Company, which is handling the return shipment to Europe.

Maersk is collaborating with Singaporean authorities and the shipping line responsible for transporting the containers "to ensure that the containers will be repatriated to Albania in the best way possible," Maersk spokeswoman Summer Shi stated, reported the Bangkok Post. 

Maersk stated that none of the containers were declared as hazardous waste; otherwise, the company would have refused to transport them, according to a letter from the shipping company posted on Thai environmental watchdog EARTH's Facebook page.  

The Basel Action Network warned earlier this month that two ships were carrying 100 containers of waste that originated in Albania to Thailand. 

“[T]he transport of hazardous wastes without the approval of the exporting country (Albania) the transit countries (such as South Africa) and the scheduled importing country (Thailand) is illegal waste trafficking under the terms of the Basel Convention,” the NGO said in a statement. 

“Already it has been confirmed that Albania was never informed about the export by the exporter and Thailand has not received any notification. Transit countries like South Africa have also not been informed prior to shipment,” BAN added.

The Thai environmental group EARTH also stepped in to urge the country's government not to accept the shipments. 

"Under no circumstances will Thailand accept being the dumping ground for the rest of the world's toxic industrial waste, electronic wastes or plastic wastes," said EARTH director Penchom Saetang, as quoted in a BAN press release.

"We call on our government ... to take the necessary actions to stop this offensive trade dead in its tracks."