Hydrogen Sulphide (H2S) badly affects seamen

By Accidents
An accident occurred on a chemical tanker during loading her cargo. The crew had to load the crude sulphate turpentine (CST), 2000 tonnes. The MARPOL Annex II gives Category X to the CST.

The crew members were experienced but not exactly with this type of cargo. They strictly followed all procedures and checliksts, including the Procedures and Arrangements (P&A) Manual and the Safety Management System (SMS) of the tanker.

The chief officer gave instructions, prior to arrival, but the material safety data sheets (MSDS) were missing and the cargo hazards were not explained properly. The crew received only generic MSDS but the toxicity of hydrogen sulphide (H2S), organo-sulphides and mercaptans were not mentioned.

Due to that,only a respirator filter was used by the surveyor. This was not effective against the vapours from the H2S. The Butterworth hatch of the tank was opened by a seaman who did not even wear a respirator.

The situation was seen by another crew member. He informed the chief officer and then the Master. He sound the general alarm on the vessel bridge. At that time, the chief officer tried to save the seaman but he was not wearing any apparatus, neither was prepared for the atmosphere. When he approached, he became unconscious. An attempt to rescue the seaman and the chief officer was done by another crew member. He held his breath but still the vapours affected him badly.

Finally, the seaman and the chief officer were rescued by other crew members who were wearing breathing apparatus. At the hospital, where they were taken, they were recovered completely.

The root cause of the accident were found:
  • insufficient MSDSs version;
  • inappropriate briefing prior arrival;
  • the strong odor was ignored and breathing apparatus were not in use;
  • the fixed washing system was defective;
  • lack of identification of potential danger, for instance - the place of the Butterworth hatch;
  • the initial rescue attempt was an act of impulse, the chief officer did not use breathing apparatus, neither the atmosphere was checked.
  • The Master did not follow terminal emergency procedures.