Brussels: Dutch authorities were struggling on Friday to respond to a possible environmental crisis after a cargo ship sailing the North Sea during a storm lost 277 giant shipping containers, including at least one carrying a toxic substance.

The Netherlands deployed 100 troops to help clean up after the Panamanian-flagged cargo ship MSC Zoe hit “heavy weather” that threw hundreds of the colourful containers overboard, the Mediterranean Shipping Co., which owns the vessel, said in a statement.

While shipping accidents are inevitable, they rarely occur on this scale.

“It does happen from time to time that ships lose a few containers,” said Wendy Geertsma, a spokeswoman for a government agency responsible for safety in the northern Dutch province of Friesland. “But never that many, and here we’re dealing with three containers filled with toxic substances, too.”

Among the thousands of containers that the MSC Zoe was carrying to the German port of Bremerhaven from Antwerp, Belgium, on Wednesday were three containing 7 tonnes of peroxide powder — each in small bags, Geertsma said. One such bag was found Thursday on a beach in Schiermonnikoog, a Dutch island near the German border. It was not clear how many of the three containers went overboard.

Organic peroxides are acids that can be used to synthesise other chemicals commonly found in disinfectants or cleaning products. They can cause minor irritation upon contact with the skin in low concentration, and can be highly toxic in higher concentration or if inhaled.

Some of the hundreds of containers thrown overboard appear to have broken open, spilling their contents into the frigid waters and onto beaches nearby, while others are thought to have sunk. A few containers were still bobbing in the North Sea on Friday, imperilling sea traffic, and 22 had washed ashore by Friday afternoon, safety officials in Friesland said.

Clothing, packaging and light bulbs have washed up on Dutch beaches, where volunteers and local politicians worked Friday alongside Dutch soldiers in cleanup efforts. The debris appears to be concentrated on the Frisian Islands of Vlieland, Terschelling, Ameland and Schiermonnikoog.

Ineke van Gent, mayor of Schiermonnikoog, called the accident a “disaster for nature” and asked for emergency help. Local authorities were also quick to warn volunteers in the cleanup not to touch any of the white bags, asking that they call emergency services workers to collect them.

Maj. Sjaak van Elten, a spokesman for the Dutch Defence Ministry, said that 100 troops had been sent to the island of Schiermonnikoog on Friday, and that they would continue cleaning up debris this weekend. He noted that Schiermonnikoog was one of the country’s “most scarcely populated islands, with the least capacity for volunteering, and it’s there that most of the rubbish is washing ashore.”

“It’s not mopping up with the tap open anymore,” van Elten said, using a Dutch expression referring to an impossible, pointless task. “But after every high tide, new stuff arrives on the beaches, so the cleaning work continues day after day.”

The Mediterranean Shipping Co. said in a statement Friday that it was using fast boats to tow drifting containers and sonar-tracing vessels for underwater recovery. It also deployed drones to try to prioritise what to recover.

The MSC Zoe has arrived in Bremerhaven, Germany, where authorities said they planned to investigate what might have happened during the storm. Dutch authorities said Friday that they were opening a criminal inquiry.

It is not clear if more than one of the containers carrying peroxide powders spilled its contents, nor how many of the bags with the toxic substance might have broken. But 7 tons of peroxide thrown into the North Sea — assuming the two other containers remained safely on-board — could do considerable damage to fauna and flora and could harm people who touch or inhale it, safety officials warned.

There is one reason for hope, however. The peroxide powder is biodegradable and loses its toxicity after roughly 30 days in contact with water, the officials said.