Confined spaces on maritime vessels present a variety of risks to workers. One must consider the nature of the atmosphere within the space, as there may be a lack of oxygen. Gases and vapors may be present, which can be toxic or flammable. There may be no means to avoid breathing these in. Plus, any disruptions to ventilation can suddenly increase exposure. Tight spaces should be continuously ventilated.
Negligence and failing to follow safety protocols can be deadly. A report in Marine Insight covered the deaths of three container ship crew members, while the vessel was in port. The goal was to fix a leaky storm valve. This required entering a tunnel, a confined space where workers had to isolate a line and work on the valve. The valve was removed, but toxic gas entered the tunnel, causing the workers inside to collapse. Safety procedures including gas detection could have avoided the incident.
In EHS Today, the use of solvents by workers at a Louisiana shipyard was cited as a danger. An oxygen hose was used to dilute the solvent, but another individual entered the space, smoking a cigarette. Putting it out on the deck caused a fire that led to fatal burns. In another incident, employees using spray painting and portable lighting equipment on a barge were killed when flammable paint vapors ignited, due to a lack of ventilation.
Precautions for Entering Confined Spaces
Precautions include evaluating the space before entry, which includes conducting tests for oxygen, toxic compounds, and flammability with calibrated instruments. Testing should be done before hot work is begun if there is oil or fuel in the area, or it recently was. Also, blowers and fans should be checked to ensure there is adequate ventilation. Protective clothing and gear, or respirators, should be used if test results indicate these are needed.
What is brought into a confined space can possibly create dangerous situations. Workers should therefore not bring paints, chemicals, or even portable internal combustion engines inside that could release carbon monoxide.
An emergency plan should be in place before something happens. Crew members should have a procedure for contacting local rescue services, and personnel should not attempt a rescue themselves, which can lead to additional fatalities.
The Occupational Safety and Health Administration (OSHA) maintains various regulations about confined spaces. These cover the general hazards, certification and testing by marine chemists, and signs indicating certification inspection results. Other regulations cover isolating areas where asbestos work is conducted, using purifying respirators and portable exhaust systems, and respiratory protection during welding and cutting operations.
OSHA standards also call for:
- Atmospheric testing in sequence, going from oxygen content to flammability, to toxicity testing.
- Proper record keeping of test and inspection results, including posting records near affected operations and having them on file for at least three months.
- Specific procedures to keep confined locations free of gas and to monitor conditions as they change.
Modernized equipment is also helping to improve safety. Wireless gas monitors, weather monitors, and biometric sensing systems are providing remote detection of hazards. In addition to real-time reporting on gases, these can track workers’ vitals such as heart rate and stress to provide more constant, detailed monitoring.