2011X41 Enclosed Spaces - Cleaning Agent
Misuse of Cleaning Agent in Enclosed Spaces
- Cape Town.
- Official Report No. 7024.
The Republic of Vanuatu commissioned an investigation into the deaths of two crew members on board a refrigerated cargo vessel registered under the Vanuatu flag. The casualty occurred in Cape Town whilst the vessel was berthed alongside. The report highlights the danger of using chemical cleaning materials in a confined space and the necessity for the correct use of breathing apparatus when trying to rescue persons caught in a toxic atmosphere.
The bow thruster compartment (btc) had been partly flooded due to a crack in the bulkhead of the adjacent ballast tank. The compartment had been pumped out and shortly after arriving in port, the third engineer (3EO) and a fitter entered in order to carry out chemical cleaning of the bow thruster motor. After they had been in the compartment for about 1 hour, they were joined by the master who remained with them for approximately 30 minutes, after which they all left the compartment to go for a tea break.
After their tea break, the 3EO and the fitter returned to the btc in order to complete the cleaning work. Approximately 30 minutes later, the second engineer (2EO) went to the compartment and called down from the top. On getting no response, the 2EO entered the compartment. About half way down the access ladder he noted a strong smell of cleaning solvent, he was prevented from entering further into the compartment by the fumes which were strong and suffocating. The 2EO immediately climbed out and instructed two crew members to fetch compressed air breathing apparatus (CABA) and to raise the alarm whilst he went to inform the master. Attempts were then made by one crew member and the master to enter the compartment, both with and without CABA. These attempts were unsuccessful despite the addition of a compressed air hose being lowered into the compartment for supply of additional air. The two casualties were eventually recovered from the compartment by the shoreside rescue service and the fire brigade but it was too late to revive them. Subsequent enquiries revealed that the two crew members had tools and cleaning materials lowered down to them in the btc by an AB and a cadet. The tools included an electric multi-meter and the cleaning materials consisted of a 20l drum of DREW ELECTRIC MOTOR AND PARTS CLEANER, some rags, paint brushes and a small open can of 0.5l capacity. The btc extractor fan was not running, it could only be started when the bow thrust was working and this had been electrically isolated for cleaning purposes. There was therefore, no mechanical ventilation of the compartment whilst the cleaning was in progress.
The cadet, being off duty, left the AB in the fo'c'sle store doing odd jobs and keeping a watch at the btc access hatch as detailed by the chief officer. After the tea break, the AB again resumed doing odd jobs whilst continuing to keep a watch on the access hatch. The 2EO arrived to check on the progress at 1130 and after his unsuccessful attempt to enter the compartment told the AB to get the CABA. On his way aft, the 2EO met the cadet and instructed him to help with the CABA. The cadet raised the alarm by banging on cabin doors and calling out for assistance forward on his way to get the CABA. After informing the master the 2EO again went forward, he was now accompanied by the chief engineer (CEO), the chief officer (CO) and the motorman. On arrival at the btc the CO saw a man's leg which was visible at the bottom of the ladder and smelt a slight smell of cleaning solvent. He went straight back to inform the master that an ambulance was urgently required. The master told him to go to the nearest security point ashore to telephone for assistance, whilst he went himself to call the harbour control on the VHF. On receipt of confirmation that help was on its way, the master went forward.
In the meantime the cadet and the AB were assisting the motorman (who was stated to be well acquainted with the apparatus) to don the CABA. The 2EO checked the bottle contents and noted the pressure of 170 Kpa. At this time the CEO was arranging a compressed air line to provide additional air. The motorman descended about half way down the ladder, he then became extremely agitated and climbed out again saying that the fumes were leaking past his face mask. His air bottle pressure was also noted to be low and a spare bottle was sent for. By this time the master had arrived on the scene and immediately put on another CABA but found that the bottle was empty. The spare air bottle was brought but due to fumbling and general panic, the crew were not able to fit the bottle to the apparatus. The shore rescue service, police and fire brigade arrived shortly afterwards and the casualties were eventually retrieved from the compartment between 1230 and 1240, over an hour after the 2EO had first realised they were in trouble.
The cleaning fluid consisted of 1.1.1. Trichloroethane. Part of the warning label on the container was damaged, this should have read "INCLUDING DIZZINESS, HEADACHE OR DROWSINESS. MAY CAUSE DEATH IF TOO MUCH IS BREATHED". The remaining section of this part of the notice actually read "EFFECTS IN G DIZZIN HEA ACHE OR SINESS. MA MUCH IS BRE D". It was calculated that concentration levels which could be reached in a compartment of this size from the use of only 0.5l of this substance are well in excess of those which the data sheet refers to as being capable of causing unconsciousness and death. This accident could have been averted if the officers had implemented the standard safety procedures when working in a confined space and the crew been properly trained in the use of breathing apparatus and in emergency procedures. The outcome may also have been different if the fan in the btc had been disconnected from the thruster and fed from an alternative supply.