The aspect of diesel workplace exposure standards in Australia revolves around ambient air quality standards in the workplace. Ambient air quality in the workplace promotes the well-being of the people using the facilities more especially in underground mining where ventilation is of the essence. Poor air quality adversely affects the health of employees leading to low performance, detriment to their health and significant cost to the business. The second most carcinogen workers are exposed to in Australia is diesel engine exhaust emissions. A decade ago, an estimated 1.2 million Australian workers were exposed to diesel emissions. Unanimous and compelling scientific evidence has shown that diesel exhaust emissions are carcinogenic to humans. In mining, ventilation becomes crucial when the human health and safety is of primary importance. In addition, besides the combustion of diesel engines and other machines certainly require better air circulation to function properly. New diesel workplace exposure standards have been implemented by the Western Australian Government. The workplace exposure standards apply to all Western Australian mining operations. Mine operators have the diesel particulate matter limit set at 0.1 milligrams per cubic metre of air in the workplace. This article investigates diesel use in Australia, workplace health and safety and control measures from exposure to diesel exhaust emissions.
A look into diesel uses in Australia – cetane number, standards, and pricing.
Standard diesel in Europe is cetane 51 and the US #1 diesel at 44/45 and #2 diesel at 40, and Australian diesel with a minimum of 46. Cetane number is an indicator of the combustion speed of diesel fuel and compression needed for ignition. Fuels with lower cetane number have longer ignition delays, requiring more time for the fuel combustion process to be completed. Therefore, higher speed diesel engines operate more effectively with higher cetane number fuels. There is only one standard for diesel fuel in Australia. So, all diesel, is required to meet that one standard of cetane rating, lubricity, density, copper/acid test amongst the other tests. All diesel is sold with fuel tax applied and off-road commercial users can claim that tax back through their business statements. The only variation with Australian diesel is the cloud point, which is the temperature at which the fuel starts to gel and go cloudy. For diesel sold in cold weather areas like Tasmania, the diesel is refined to remove more of the waxy components so that it stays liquid at lower temperatures. There is “special” diesel which costs slightly more and its difference from “truck diesel” is that it smells better and does not foam as much when filling up, hence less chance of splash back. The price of diesel in Australia is twice as much as in America. This is because of tax, where a certain 40-50 cents per litre value for excise duty is added to the wholesale price and then 10% is added to the retail sale price at the pump.
Workplace safety and health – diesel exposure in Australian underground mines.
Underground mining activities that use diesel produce emissions and the dangers of diesel emissions pose health threats to underground mine workers. Diesel particulate matter, sulphur dioxide and carbon monoxide are amongst the many health hazards exposed to underground mine workers. You can get carbon monoxide largely from underground mining equipment. It can displace oxygen and suffocate underground mine workers. But why is there preference for diesel over petrol in underground mines? The answer lies in that petrol vapors are heavier than air which if emitted from a continuous source, they would accumulate over time at the bottom of the mine shaft. Over time, the concentration of the gasoline vapors and air would become enough that it would be combustible. Diesel vapor is lighter than air and would have a natural tendency to rise out of the mineshaft into the atmosphere. Diesel engines produce better torque than petrol engines, which enables big haul trucks used in the mining industry to provide better torque to carry heavy loads with proper acceleration. Cancer risks from diesel engine exhaust emissions vary depending on location of the operating engine (outside or enclosed space), ventilation in the workspace, number of engines, type and age of the engine, size of engines, fuel pump settings, engine temperature, fuel used (low-sulphur diesel), use of emission control systems, state of engine tuning and maintenance, patter of use (load and acceleration) and length of time the worker is exposed. The importance of underground mining ventilation cannot be understated. It helps improve flow of air, dilute and remove noxious gases like carbon monoxide and efficiently regulates temperature. As we finalize the discussion, we investigate control measures that can be implemented to minimize exposure to diesel engine exhaust emissions in Australia.
Are environmental regulations, health and safety concerns or potential profit loss a concern right now?
Control measures from exposure to diesel engine exhaust emissions in Australia.
A hierarchy of controls should be put in place for anyone working with or around diesel-powered engines to reduce the risk of developing cancer. The intention is to impose controls starting from personal protective equipment, administrative controls, engineering controls, substitutions and if possible, eliminate which is at the apex of the hierarchy of controls. Workplace air monitoring can be used to check if exposure to particulate matter from diesel exhaust engines is being effectively reduced by the controls being used. There have been factors that affect the incidence of cancer risks and for each of those factors, there are certain control measures that can be implemented. We highlight some of the activities and controls in a summary of control measures for diesel exhaust emissions.
- Engine selection – replace diesel-powered engines with other energy sources or choose low emission engines
- Fuel selection – use ultra-low sulphur or other low-emission diesel fuels, fuel additives and low sulphur lubricants where possible
- Engine refurbishment – refurbish engines to use low-sulphur fuel and to improve fuel efficiency
- Emission control devices – install devices that reduce emissions, these include particulate filters, catalytic converters
- Ventilation – use both local exhaust and forced dilution ventilation.
- Engine operation – operate engines to optimize combustion with efforts such as drive to usual conditions, limit idling and over revving.
Exposure to diesel exhaust emissions is hazardous to human life. It is import for workers that are in workplaces that expose them to diesel emissions to be educated and trained about the hazards, policies, and procedures to manage their workplace safety and health. Training should include how to recognize and report any changes in engine emissions or visible changes in the workplace. Workers should be taught how to operate equipment to minimize emissions. Administrative controls like sharing activities can also reduce amount of time workers are exposed to diesel exhaust emissions and as a last line of defence PPE should be used as protection that filters particulates.
Your feedback is important to us. If you enjoyed reading this Global Road Technology industry update and found it informative, please let us know by leaving a REVIEW.
REFERENCES
Cancer Council. 2021. Diesel engine exhaust and cancer. Retrieved 16/04/21
