One person died, and five others became seriously ill after reportedly drinking cleaning liquid earlier this week aboard a floating production, storage and offloading unit (FPSO) being transported by Boskalis' Vanguard heavy-transport vessel.

Boskalis said Thursday: "Earlier this week, an incident occurred on board of the FPSO which is currently being transported by the Vanguard from China to Brazil."

"During the journey, a contractor, designated by the yard, is conducting preservation works on board of the FPSO. These works are part of the pre-delivery activities by the yard before the FPSO is delivered to the operator in Brazil later this month. Six persons employed by the designated contractor, all with the Brazilian nationality, illegally consumed a cleaning liquid found on board of the FPSO."

According to Boskalis, the liquid is a substance usually used for degreasing purposes, presumably containing a mixture of ethanol and the severely toxic methanol. 

"The affected persons reported this to our crew approximately 36 hours after consumption, at which point serious signs of illness were becoming apparent. Swift and immediate action was taken by our crew. The Vanguard changed course towards the coast of South Africa and medical evacuation by helicopter was organized. Regrettably, one of the affected individuals passed away before the medical assistance was on site," Boskalis said.

"The remaining five persons were successfully evacuated, hospitalized in Durban, South Africa and are successfully recovering from the intoxication, Boskalis expresses its deepest condolences to the family and loved ones of the deceased person," Boskalis added.

The FPSO and Vanguard resumed their journey to Brazil. According to NSRI Durban, the body of the Brazilian adult male who died aboard the FPSO man remained on the ship at Captain's request. 

While Boskalis did not provide details on the FPSO and the end client, images shared by NSRI Durban show the FPSO is on its way to the Brazilian oil company Petrobras.