200545 Coconut Oil Hazard

Coconut Oil Hazard
MARS Report 200545

A vessel on her maiden voyage carried a full cargo of Crude Coconut Oil. Part of the cargo was discharged in Spain and the balance in Northern Europe. No tanks were emptied in Spain but all were emptied in the second port. Before starting discharging in both ports, a safety meeting was held by the personnel concerned during which safety and communication procedures were agreed upon.

Vegetable Oil requires a "squeezing" of cargo as a final step to make tanks as dry as possible to minimise the remains on board (ROB). As agreed between the master and the terminal operatives, the squeezing of the cargo was planned to be done by the crew and not by the shore team. No particular precautions to deal with this cargo were addressed to the vessel by the terminal operators.

Crude Coconut Oil is not difficult to squeeze compared to other vegetable oil grades. The temperature of the cargo was about 400C. Based on the above, monitoring of ROB was done only from the tank dome and no advance entry to check for possible accumulation of sediment was carried out in the tank. Only at the last moment was this considered necessary. When the cargo discharge was almost completed, the master and 2 other crew members entered the tank with the intention to carry out the required squeezing as described above.

During discharge, the high velocity PV valve was kept on a free flow mode (cover of vacuum side was kept open). Furthermore 6/7 hrs before entering the tank, the tank dome was completely opened and the IG blower was started running on the fresh air mode. However, the IG inlet was opened on all cargo tanks, a safety poster was displayed next to the dome, the poster warned people against entry without prior permission of the chief mate or responsible officer authorisation.

Before entering the tank, the required checks to issue the Entry Permit were carried out and a breathing apparatus was kept ready for use next to the tank dome. The Entry Permit was issued based on the Company's Check list. Checks of Oxygen (O) content as well as LEL (lower explosive limit) were carried out.

The master was carrying a walkie talkie as well as a personal gas detector (combined O and LEL) and the chief mate and pump man were standing on deck. Before entering, a radio check was carried out and communication was kept active while entering. Once the master and the other 2 personnel reached the tank bottom, they realised that it was becoming difficult to breathe and immediately started evacuating the tank.

Thankfully, they reached the upper platform which is about 3 meters inside the tank and thanks to the prompt reaction of crew they were immediately evacuated and hospitalised for treatment. As soon as people from the terminal boarded the vessel, they asked if the Entry Permit was issued before entering and if all parameters were checked to make sure that the atmosphere and conditions were suitable to grant a safe squeezing.

Before entering, as required by our policy (cargo operation manual and by the good practice), the O and LEL were checked and found as required, O = 20.9% and LEL = 0%. The check was done with a GMI combined instrument which gives 3 readings simultaneously i.e. O content, LEL up to 100% if in air and then automatically it passes on to volume % when in excess of 100% LEL, or it gives directly HC % in volume if tanks are inerted. The ventilation from an IG (inert gas) blower was on but the IG inlet was opened on all cargo tanks.

Once the heat of the moment was over, the terminal manager asked if, during preliminary control for entry, CO content was checked, this check was not done but it was immediately done after the terminal informed us that CO could have been the reason of the casualty. By using a DRAGER pump we checked the CO content in all tanks and we found that all the tanks had CO concentration in excess of 3,000ppm.

ANALISYS OF THE NEAR MISS

The Company Management were not aware of the possibility of CO content in the Crude Coconut Oil. In the recent past, identical operations were carried out dozens of times on sister vessels. Underestimation of health hazard of this cargo is the main reason of the near miss. Checks for CO, H2S and Benzene as per our SMS policy and as specified in the Entry Permit Form is required only for specific cargoes.

Ventilation was on (1 IG fan running) but because we didn't expect CO emissions from the cargo and, since the temperature inside the tank was about 320C and the liquid was 400, however, as the external temperature was in the range of 18/20, the ullage space was cooling down very quickly. The ventilation was opened on all tanks and I would say it was maintained as an extra precaution and not considered as the main safety measure as it should be. With the ventilation opened in all tanks it undoubtedly is not getting the required effect Air is entering at very low pressure, and without producing any turbulence it exits via the closest opening to the IG inlet. Port State Control, who attended for the investigation in fact didn't consider the ventilation in this mode efficient enough to eliminate the CO concentration and have assumed the entry was done without required ventilation.

All the free flow on the high velocity valves were opened and also on all tanks where the discharge was occurring. The tank dome was not tight but all securings were loose and air was also easily passing from there. The Marine Safety data Sheet (MSDS) was posted and since the summary of risk states that "CRUDE COCONUT OIL IS NOT HEALTH HAZARD", no extra precaution was taken to deal with this cargo.

OPERATIONS ON THE VESSEL

The vessel followed the Company policy and the Material Safety Data Sheet. Personnel who entered the tank were wearing safety belts (that is why they were evacuated easily and in a few minutes), breathing apparatus was available on deck and this is why the pumpman rapidly donned it and could immediately enter the tank.

Good training to deal with a casualty has given a good result and has saved the lives of 3 persons.

CONCLUSION

We have investigated the matter and have learned the following lessons.

1. When insufficient data is available from known sources further investigations have to be carried out to eliminate any doubt. Despite the MSDS stating that the Crude Coconut Oil is not a health hazard, we have never investigated the possibility with the terminals in Europe (although it now transpires that they already had better knowledge of the hazard of these grades of cargo). As far as we know, FOSFA (The Federation of Oils, Seeds and Fats Association) don't give any official advice in this regards, but the terminal was well aware of the risk and a simple investigation could have disclosed it (apparently, in the past months a similar case has ended with the death of a crew member).
2. Carbon Monoxide has often been responsible for the death of vessel's personnel, a simple combined gas detector which has a sensor for CO incorporated would have alerted the crew of the presence of a high concentration of CO and consequently would have avoided such a hazardous situation.
3. Ventilation running in a proper way would have diluted the CO concentration below the risk level.
4. Personnel entering tanks must also carry a CO detector together with O and LEL personal detector, (as per company policy when entering tanks after carrying Crude or Fuel Oil. An H2S detector has also to be carried).

ACTION ALREADY TAKEN

1. The Company Management has enforced temporary substitute procedures to make sure that entry is not allowed into cargo tanks if CO content concentration has not been checked and shown as 0ppm irrespective of whether present or previous grade of cargo carried is a Hydrocarbon or not.
2. Forced ventilation which gives a sufficient turbulence for an continuous atmosphere exchange (1 tank at a time, either with an IG blower or a portable air or water blower of a minimum of 4,000M3/hr capacity) to be maintained running during entire personnel entry.
3. Remaining enforced restrictions/requirements remain in force until amendment to the SMS will be defined, approved and distributed to the fleet.

The Company's SMS is being amended to reflect the above requirements.

UK MCA Marine Guidance Note MGN 223 (M) warns of the possibility of CO gases building up during carriage of Coconut Oil. RB