On completion of discharge, six men entered one of the cargo tanks to sweep the residue cargo to the pump suction. A few minutes later, it was noted that the men in the tank suffered from unidentified problems. Of the six men, four made their way out, whereas the remaining two collapsed, falling over the heating coils in the tank. Subsequently, one man died.

The oxygen level of the tank, as well as the LEL (lowest explosion level) was checked and considered normal for safe entry. Thorough investigations and analysis by a laboratory revealed that the tank contained more than 1000ppm carbon monoxide (CO) which is a dangerously high level for human exposure.

The development of CO in the tank vegetable oil was unknown and even provoked the chemist to express initial disbelief. Analysis however, showed that CO was forming in samples that were being heated in the laboratory, to a dangerously high (fatal) level. Other samples from another shipment also showed too high a CO content.

Consequently, the MCA strongly recommends checks being made for CO before entering into a cargo tank containing heated vegetable oil. An advisory MGN is to be issued.

Source of information: (

or on Ext. 2827)