A Panamanian container vessel ran into a Chinese cargo ship in foul weather on Sunday in the port of Tianjin, north China, causing dangerous chemicals to spill into the sea, according to port sources.

At 10:00 PM Sunday, in heavy rain and dense fog, the Panamanian vessel loaded with containers bumped head-on into an internal-trade ship while waiting in the sea-lane for suitable weather to sail towards Japan.

The tip of the Chinese vessel damaged containers filled with furfuryl alcohol, a toxic and flammable chemical, on the second deck of the Panamanian vessel. It was immediately washed into the sea.

Furfuryl alcohol is used in industrial processes and is an irritant that can, in strong enough concentrations, cause tumors and genetic mutations.

Port workers are still unloading the containers from the Panamanian vessel, and the condition of the tainted sea-lane is being closely monitored.

At 5:00 AM Monday, an anchoring Chinese coaster collided with a tanker of the China Marine Bunker Supply Tianjin Company while it was being fueled. Oil spilled into the sea, but was brought under control.