Workers most likely to be exposed to diesel exhaust include drive-in booth operators, miners, construction workers, oil and gas workers, forklift drivers, loading dock workers, truck drivers, farmworkers, stevedores, and vehicle maintenance workers. 

The major source of workplace exposure to diesel exhaust is from heavy vehicles that use diesel fume like trucks, buses, trains, tractors, ships, bulldozers and fork lift trucks.

This webinar will show you where there may be diesel exhaust hazards in your workplace, how you can evaluate the risk of exposure (including how to go about air sampling), when it can start to become a major problem, and how you can reduce the risk of exposure to diesel exhaust in the workplace.

Who is this presentation for?

This webinar is for businesses of any size where workers may be exposed to diesel exhaust, like in vehicle repair workshops, tunnels, partially covered roadways and walkways.

Business managers, workers and worker representatives will find valuable information on how to protect themselves and their workmates. Work health and safety regulator staff (inspectors and advisors) and work health and safety professionals, industry bodies and others who offer advice will also find helpful information in this video.

About the presenter

Jen Hines and Dr Brian Davies are both occupational hygienists. Occupational hygienists help businesses to identify and eliminate or control workplace health hazards.

Jen has been working as an occupational hygienist for over 15 years and works across a variety of industries including large underground mining operations and small to medium sized businesses.

Brian is an industry leader in ways to control diesel particulate matter. He has worked in various industries including steel, mining, aviation and education and has been involved with the issue of diesel emissions since the mid-1970s.

Useful resources



What's that cloud? Dangers of diesel exhaust fumes for business

Australian Institute of Occupational Hygienists Inc

Ms Hines: Hi and welcome to “What’s That Cloud?” the Dangers of Diesel Exhaust Fumes for Business.  Brian and I are occupational hygienists.  Occupational hygienists help companies understand risks to health at work, and how to improve working conditions and working practices. 

We use science and engineering to prevent illness and disease in places where people work.  We do this by understanding contaminants, hazards, and processes that may affect the health of a worker.  We then help both employers and workers to prevent exposure to the contaminants by controlling the exposure.  This could be by removing the contaminant away from the workers, substituting it with a lesser harmful substance, using ventilation, or by containing it to reduce exposure to name a few methods.

In some cases exposure can also be controlled by using personal protective equipment, or PPE, and occupational hygienists get involved in making sure that it is the right PPE for the job, and to make sure that it fits and is used properly.  We might need to test the work environment to understand how much of a contaminant is present, and if it is likely to be enough to cause ill health to workers. 

Today we are going to talk you through how you understand if you may have a diesel exhaust hazard in your workplace, how you can evaluate the risk of exposure, including when and how you might go about sampling it, when it can start to become a major problem, and how you can reduce the risk of exposure to diesel exhaust in the workplace.

Exposure to diesel exhaust fumes can cause both acute or immediate effects, and chronic or long term effects.  Long term health effects doesn’t mean you will be sick with the disease for a long time, it means that you won’t know you are sick from exposure until a lot later in life.  Humans often forget about or dismiss long term health effects because we are so busy living for now.  This is one of the reasons that reducing exposure is very important.

So that’s what the webinar is about, and why we are talking to you.  But you should also know who we are.  My name is Jen Hines.  I have been working as an occupational hygienist for about 15 years, and during that time have developed an interest in measuring and controlling diesel engine exhaust.  I have worked with a large underground mining operation, as well as small to medium sized businesses to assist in assessing and reducing exposure to their workers.

Mr Davies: I’m Brian Davies, and I’m also an occupational hygienist.  I have worked in steel, mining, aviation and education industries over my career, and have been involved with the issue of diesel emissions since the mid 1970s.  In fact I undertook a PhD in the control of diesel particulate in underground coal mines, and many of the findings of that research can be equally applied to any workplace.

Okay, so now let’s move on to what is in diesel engine exhaust and its associated hazards.  We will provide you with information about diesel emissions and how you can protect your workers and business.

Firstly let’s take a look at what diesel engine exhaust is.  What is in that cloud that should concern us?  Diesel or exhaust is a complex mix.  It is made up of gases and small particles.  The gaseous phase is generally made up of the same gases as found in air, as well as a few other not so desirable gases.  The gases include nitrogen dioxide, nitric oxide, carbon dioxide, carbon monoxide, other irritant gases, and water vapour.  Several of these gases, such as carbon monoxide and nitrogen dioxide, present serious health risk to workers at relatively low concentrations if not controlled in the workplace.

The small particles or particulate phase of diesel exhaust has a very small carbon core surrounded by tiny droplets of organic compounds, and this is what is known as diesel particulate matter, or DPM.  Both the DPM and the gases in diesel exhaust are cause for concern, and we will discuss this more fully in a few minutes.

So firstly we need to determine if diesel exhaust may be a health risk in your business.  We do this like you do any other risk assessment.  You need to identify the hazard, assess the risk, control the exposure, and then review and ensure your controls are effective.

Ms Hines: So the first part of this, identifying the hazard.  Starting simple.  Do you have diesel powered machinery in your workplace?  Big, little?  A couple of engines?  Lots of engines?  

Mr Davies: Do you walk into your workplace and notice a smoky haze of fumes accumulating in enclosed or closed in areas that don’t get a lot of ventilation, or maybe the roller doors are shut during winter because it’s cold, and that’s when you see the fume.  Perhaps a warehouse, underground car park, diesel workshop?

Ms Hines: Do you notice any sooty deposits on walls or permanent fixtures?

Mr Davies: Do you smell exhaust during your work day?  Do you only notice it first thing in the morning?  Is it intermittent or there all of the time?

Ms Hines: Do you find yourself coughing more at work than when you are away from work?  Do your eyes water or become itchy when diesel machinery is operating?  If yes to any of these things, then it is a good idea to continue listening in on this webinar, as it is most probably applicable to you, your workplace, or business.  

Mr Davies: If you’re still not certain who may be exposed to diesel exhaust, here are a few of the more common small to medium businesses we find may have diesel exhaust exposure.  Diesel workshops or vehicle repair facilities, tunnelling projects, warehouses, underground mines, coal or metalliferous, surface mines, railways, bulk handling storage areas where forklifts or trucks are operating, trucking companies, ships’ hulls, construction, cars, car parks, farms.  There are plenty of others, and I’m sure there are people screaming at their computer screens right now trying to get me to hear other industries that they know or work in where there is exposure to diesel emissions.

Another good question is “Why are we actually interested in this anyway?  Who cares if there is a bit of diesel fume around?  It’s been there for years.  We’ve always worked this way, my dad worked this way and there’s nothing wrong with him”.  These are all familiar things we hear in workplaces.  But in June 2012 diesel exhaust was confirmed as a Group 1 carcinogen, which means it definitely has the ability to cause cancer in people.  It is known to cause lung cancer and to a lesser extent, bladder cancer.  It is also very irritating, causing workers’ eyes to water, and coughing.  If it is bad enough there are additional safety issues through reduced visibility.  If it is going to cause cancer, it’s likely to have a long latency period, which means it may to take 10 to 30 years until health issues show up.

Ms Hines: Okay, so now you know that you do, or perhaps don’t, have diesel exhaust within your workplace, and that it’s pretty nasty stuff.  And so you would like to find out if you have a problem.  So how do you do this?  There are a couple of things you can do here.  We’ll start with the simple stuff first.

If you have diesel powered equipment inside a building or an enclosed area without any forced ventilation, then you shouldn’t waste your time sampling it, you most probably have a problem.  So start to focus your efforts in replacing it with electric equipment, or look at whether you can move it outside.  Sounds obvious, but we see things like generators being used in basements rather than using extension leads and moving the generator outside.

If you feel you’ve done all you can and you’ve still got diesel fumes in the work area, then it might be time to do some sampling.  This is where occupational hygienists come in.  We put sampling devices on workers to measure the amount of DPM and/or gases, to be able to tell you exactly how much that person was exposed to, and if it was a cause for concern.

Mr Davies: The other thing that you can do is to measure the exhaust from your machines and see how much exhaust they are producing.  Understanding how much diesel exhaust is coming from your machines also forms part of controlling exposure, so we will talk about this more fully shortly.  

One of the big questions is “How much is too much?  How much is safe for me to breathe in?”.  This is a good question, and there are many hygienists out there waiting for the science boffins to provide us with that answer.  There are a number of industries that are working towards an amount of 0.1 milligrams per cubic metre as the amount that people can breathe in, and the irritant effects are unnoticeable, and likely the cancer risk is reduced.  But how much is 0.1 milligrams per cubic metre?

This is 0.1 milligrams of elemental carbon per cubic metre.  A cubic metre equals 1,000 litres of air.  Yes, this is a bit confusing, because not only have I just started talking about some strange number, but I have also started talking about elemental carbon instead of diesel exhaust.

Elemental carbon is the accepted surrogate contaminant to measure for diesel particulate.  Don’t worry too much about this just yet, because we are going to give you some helpful references at the end of this webinar.  The important thing to understand here is that 0.1 milligrams per cubic metre appears to be the maximum amount allowable, but many industries are working to much lower than this.

Ms Hines: Employers should be conscious of reducing exposure to diesel emissions in their workplace by using what is referred to as the hierarchy of controls.  The hierarchy of control is a common sense approach to methodically investigating ways to reduce exposures to the best possible advantage.  The top of the inverted triangle is the best solution.  It means that you totally remove the hazard.  The bottom of the triangle, PPE, although often used first, is the least preferred method.  Let’s take a look at each of these levels directly in relation to reducing diesel exhaust exposures in the workplace.  

Elimination.  Can you stop using diesel in your workplace?  Perhaps you’ll hire a forklift, or have a diesel forklift that is soon due for replacement.  Replacing it with a gas one may be an option, however this will not remove the gaseous emissions, only reduce the particulate emissions, which is still a good outcome.  Alternatively, you may be able to use a heavy duty electric forklift, rather than one powered by an internal combustion engine.  So have a look at all the options before you buy any replacement.  Substitution is our next option.  Maybe there is a better lower emitting diesel fuel that can be used.

Mr Davies: Isolation and engineering are often considered together.  You can isolate the worker from the exposure by putting them in a properly filtered and ventilated cabin.  Engines that are correctly repaired and maintained produce lower diesel exhaust.  In fact, it has been shown in the mining industry that both gaseous and particulate emissions can be reduced significantly by the use of an emissions based maintenance program.  These programs require regular testing of the raw exhaust of the engine, and with some training it is possible to identify maintenance issues that when fixed reduce the emissions at the tailpipe.  Such programs often have the added benefit of greater productivity, as the engine is operating to its best performance.  Emissions can also be reduced by fitting it with an exhaust treatment device.

Administration is our second last option, and this is around job rotation so people aren’t exposed for their full shift, restriction in vehicle movements or running in idle for extended periods, not starting up lots of machinery together, not driving in convoy, and very important is education and awareness for the workforce, so they can understand the risks and are more likely to help control exposures.  Having job procedures in place, ensuring that fuel put into machinery is clean, directing exhaust away from the people.

And the last level of control is PPE, or personal protective equipment, and in this case, respiratory protection.  Now we hygienists like to say this is the last option.  But it can be the first, so that workers are protected immediately.  But the important part of this is that control options are reviewed from the top again, in the hope to try to remove the need for PPE.  PPE must be right for the contaminant, be managed and fitted properly.

Ms Hines: So if employers are doing all of the above to reduce exposure, what can the workers do?  The answer to this is lots.  The employees should understand and take the hazards seriously.  While it might be something that doesn’t seem to be a big issue for them right now, it’s sometimes difficult to understand and accept that unless they protect themselves now, they may suffer ill health effects further down the track.

Workers should do all that they can to reduce the generation of diesel exhaust and their exposure to it.  They need to drive or operate diesel equipment properly.  They need to ensure that cabins are shut, seals on cabins are sound, and filters are cleaned.  They need to ensure they don’t sit in their vehicle while it is idling for no reason and expose everyone else to the fume.  If they have to wear respiratory protection, they need to make sure it fits properly, that they are clean shaven, and that they wear it properly all of the time that it is required.  Employees should also have the opportunity to make suggestions to reduce exposure.

Mr Davies: We said that diesel exhaust is a carcinogen, and can be harmful to workers’ health in other ways through irritation that may cause asthma attacks and other respiratory symptoms.  But it can also cost your business money through lost work days, lower productivity due to unhappy, unhealthy workers, and machines not operating efficiently, as well as hefty compensation claims if workers are proven to be sick due to exposure at work.  

Another very good reason to understand and reduce the risk to your workplace from diesel exhaust is to help provide a safe place of work.  This is an obligation to all business owners in Australia, under the Work, Health and Safety Act and the associated work, health and safety regulations.  These do differ slightly between states, but in a general sense you need to maintain a work environment that does not present a risk to health and safety, so far as reasonably practicable.  If you can show you are managing the hazards and reducing the risks, then you are well on your way to abiding by the law, and most importantly, looking after the health of your workers.

Ms Hines: Along with this webinar, we have also developed a simple diesel emissions checklist that can be used as your first step in your risk assessment.  It can be downloaded and used to determine if there is a risk.  In addition to this we have produced a one page flyer for you to provide to your workforce to assist them with their understanding of diesel exhaust, and how they play a role in reducing exposure.

To find a bit more information on diesel exhaust emissions, there are a couple of good publications to start you off at the AIOH.  The AIOH is the Australian Institute of Occupational Hygienists, and is the largest and only professional society representing qualified occupational hygienists in Australia.  The AIOH has a position paper, “Diesel Particulate Matter and Occupational Health Issues”, that is available to download free of charge from their website, as well as a more comprehensive document that can be purchased, “A Guideline for the Evaluation and Control of Diesel Particulate in the Occupational Environment”. 

There is a lot of information available on diesel exhaust exposure and controls.  An initiative launched in early 2015 is the UK based “No Time to Lose” campaign.  The website has a lot of freely downloadable information.  The UK Health and Safety Executive also has some great toolkits of information available to download.  

Mr Davies: We hope that you found this webinar useful to help you manage exposure to diesel exhaust in your workplace.  If you need assistance in identifying specific control measures, or are in need of an assessment of diesel exhaust in your workplace, you can consult the AIOH website, where you will find a consultant directory of occupational hygienists willing to help you.  

As a bonus, if you are a small business in New South Wales, WorkCover offers a rebate of up to $500 under their small business rebate program, which was put in place to help small businesses fix safety problems across five common risk areas, and chemicals and dangerous goods is one of them.  There are rebates available for the installation of safe ventilation, exhaust or extraction systems, air filter systems for machinery, as well as other controls.  I encourage you to look, for you to visit the WorkCover web page for further information and to look for similar programs in your home state.  Thank you for taking the time to view the webinar and to listen to our recommendations on controlling diesel emissions.

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