An ongoing investigation by the Socialist Equality Party
Cyanide gas alarm in coke ovens
Potentially fatal levels of hydrogen cyanide gas have been detected inside the coke ovens at BHP's Port Kembla steelworks.
Personal monitoring of workers has revealed that they are at times exposed to levels in excess of 110 parts per million (ppm) -- the level at which death can swiftly occur.
BHP last month undertook limited monitoring of a selected number of workers after two contractors working in the gas processing area reported to the ambulance station with symptoms of headache and nausea after a suspected gassing.
According to an internal BHP report: "The [BHP] Environment Department immediately tested the area for a variety of gases and detected hydrogen cyanide levels above the peak exposure guideline of 10 ppm. Hydrogen cyanide is emitted from various gas processing vessel vents."
Test results handed to workers by BHP state that 80 percent of readings are below the recommended ceiling limit of 10 ppm. Translated into plain language, one-fifth of all readings exceeded the safety limit.
Monitoring of a valveman at the number 3 battery found that he was exposed to levels above the 10 ppm safety limit for several minutes on five separate occasions during a single day. One two occasions the monitor went over the 110 ppm mark.
BHP's results were accompanied by a Cyanide Management Guideline issued by the West Australian Department of Minerals and Energy which states: "110 ppm can be FATAL".
The document also states: "The fastest route for cyanide to enter the bloodstream is by inhalation, since HCN gas is transferred via the lungs directly into the bloodstream...
"Workers must not be exposed to HCN (hydrogen cyanide) concentrations above 10 ppm at any time...
"HCN gas can kill rapidly once it exceeds the body's ability to cope. At concentrations slightly above 40 ppm, symptoms which may occur include weakness, giddiness, dizziness, headache, confusion, a drop in blood pressure, and nausea and vomiting.
"Breathing is rapid and deep at first, then becomes slow and gasping. The skin appears bright pink or red. The victim may feel an irregular heart beat and tightness in the chest. Uncontrollable urination and bowel movements may occur. Unconsciousness, convulsions and death quickly follow."
The guideline also warns of permanent damage to the central nervous system and damage to the retina and nerves of the eye, leading to impaired or lost vision.
Another part of the report issued to workers by BHP reveals that a gas level of 100 ppm was recorded at the eastern end of the number 4 battery ram bench, prompting atmospheric tests at other spots in the numbers 4, 5 and 6 batteries. The report does not explain why such tests were not conducted in the number 3 battery, the oldest and dirtiest at Port Kembla.
The results, showing levels between zero and 25 ppm, are suspect. In BHP's own words: "Care was taken not to saturate the unit (i.e. place it right into a gas leak at the leak source) as it takes some hours for the unit to return to a useable condition."
In other words, the monitor was kept away from leaks to prevent readings which went right off the scale. The report argued that workers would not normally be in the position of the actual leak, but the personal monitoring results confirm that they are regularly working very close to leaks which do expose them to potentially lethal doses.