Styrene is classed as a possible human carcinogen by the US Environmental Protection Agency, writes Dick Ahlstrom, Science Editor. It is a colourless, oily liquid that has a distinctive, strong odour and is used extensively in the manufacture of polystyrene plastics, protective coatings, rubber and resins.
It can cause health effects if breathed in as a vapour and can pass through the skin. It causes eye, skin, nose and throat irritation. Very high exposure levels can cause liver damage and possible death. Long-term, low-level exposure can cause depression, headache, fatigue and weakness.
The US has set legal exposure limits for styrene at 100 parts per million but there are efforts to halve this. If the styrene is released from the cargo holds, workers involved in containing the spill would have to wear protective clothing, goggles and face shields.