If you work with automobiles, you must be familiar with exhaust fumes. These are the fumes released when fossil fuel is burned to power a vehicle. However, are you aware of the health risk of these emissions?
Here’s the thing:
Exhaust fumes are made up of a variety of things, and the composition changes according to the fuel being used. However, even though the amount may vary, the essential components remain the same.
What Are Exhaust Fumes Made Of?
Exhaust emissions are a mix of gases (carbon dioxide, carbon monoxide, benzene and some other aromatic hydrocarbons, nitrogen, and water vapour) and particulate matter (mostly soot).
Some of the gases are not toxic, so it’s not all harmful. One of the non-toxic gases is water vapour, which is really not dangerous at all.
On the other hand, the toxic gases include carbon monoxide, which can be extremely lethal, capable of killing a human being even in concentrations within minutes.
So, you know, a healthy balance!
Let’s discuss the non-toxic gases first, just to get them out of the way.
Non-Toxic Gases in Exhaust Fumes
Non-toxic gases in exhaust fumes don’t adversely affect us, at least not in the quantities they are present in vehicle emissions.
Water Vapour
Water vapour is the only truly non-toxic gas found in exhaust fumes. Unlike steam, which is water heated to boiling-point, water vapour is naturally evaporated water. It’s not hot enough to scald or hurt us in any way.
In fact, if you follow the weather, you’d have noticed the humidity score, which is just the amount of water vapour present in the atmosphere, and it can go up to 100% without affecting us.
So how is water vapour a part of vehicular emissions?
When any organic fuel burns, it produces water vapour and carbon dioxide. You produce both these gases in your body as well when you exhale. Our cells use glucose (a sugar, which is a classification of organic compounds) as fuel to produce heat energy, and carbon dioxide and water are the by-products.
Carbon Dioxide
Carbon dioxide (chemical formula: CO2) is the second important by-product of burning any organic fuel.
Any organic material, by its very definition, is made up of carbon and hydrogen atoms. The molecules of organic fuel burn, or oxidise, in the presence of oxygen to produce carbon dioxide (one atom of carbon combined with two atoms of oxygen) and water (two atoms of hydrogen and one of oxygen).
As we mentioned earlier, all living things produce carbon dioxide (even plants; they produce oxygen through photosynthesis, but they also respire, where they take in oxygen and let out carbon dioxide). It is found naturally in our air, but its concentrations are very low – about 0.04%.
It can be toxic, but humans only start feeling any ill effects when its concentration is higher than 5%, though it can cause death in quantities over 10%. However, ordinary exhaust fumes don’t contain very high amounts of carbon dioxide so this is not a potential hazard in this context.
Nitrogen
Nitrogen (chemical symbol: N) is another gas that is found naturally in the air we breathe. However, unlike carbon dioxide, it is a whopping 78% of our atmosphere. Essentially, almost 80% of the air we inhale is nitrogen.
Again, like carbon dioxide, nitrogen can be lethal in very high or concentrated doses, but in exhaust fumes, for all intents and purposes, it’s harmless.
Toxic Gases in Exhaust Fumes
Unlike the non-toxic gases, toxic gases in exhaust fumes can cause lasting damage or even death.
Benzene
While there are other hydrocarbons present in vehicle exhaust gases, the most prevalent and dangerous of them is benzene (chemical formula: C6H6). Benzene is a liquid that vaporises really easily, creating fumes. It has a sweet smell, making it easy to detect.
With long-term exposure, this chemical affects the cells in our bodies, causing them to work improperly. It can affect the bone marrow so the body does not produce enough red blood cells. It may also affect the immune system.
Benzene has also been linked to leukaemia.
If you inhale high levels of benzene fumes, you will start experiencing drowsiness and dizziness, heart palpitations with irregular heartbeat, confusion, tremors, and headaches.
Prolonged exposure to high levels of these fumes will cause unconsciousness, whereas very high levels will lead to death.
Sulphur Dioxide
Sulphur dioxide (chemical formula: SO2) is another gas with a distinctive smell, making it easy to identify and detect. It is created during volcanic activity, which is why it’s found in higher concentrations around volcanoes.
When inhaled, this exhaust fume gas will irritate your nasal passage, throat, and airways. It can lead to irritation, shortness of breath, coughing, wheezing, and a sensation of tightness around the chest. Most people will start feeling the effects of the gas almost immediately, within minutes of inhaling it.
If you happen to be exposed to it over a long period of time, it can lead to asthma or other respiratory conditions.
Carbon Monoxide
Carbon monoxide (chemical formula: CO) is the deadliest gas in the exhaust fumes mix. It is colourless and odourless, so you can’t detect it in the air. However, even 0.0035% of carbon monoxide in the air inhaled constantly for six to eight hours can result in symptoms of carbon monoxide poisoning.
What Are the Symptoms of Carbon Monoxide Poisoning?
The initial symptoms are light-headedness, confusion, and an achy head. Long-term exposure to this exhaust fume gas can also cause damage to some organs in the body.
However, if the concentration goes up, it can cause death in minutes – less than 3 minutes, if the concentration is 1.28% or higher!
Now, I know you might be thinking carbon dioxide is also made up of carbon and oxygen. How is carbon monoxide produced when those two elements should be making carbon dioxide?
You see… carbon is a very special element. It does not mind how it combines with oxygen. If a carbon-based fuel is burning in the presence of enough oxygen, it will produce carbon dioxide. However, in an enclosed space where there isn’t enough oxygen, it will burn to produce carbon monoxide.
Exhaust gases are a result of fuel being burned in a small chamber in the vehicle, which means there is a limited amount of oxygen.
Carbon monoxide is the reason why you shouldn’t have a fire inside a room without proper ventilation.
It is also the reason why carbon dioxide is not a big threat when in exhaust fumes. If you’re in an enclosed space where the fumes are building up, yes, the CO2 levels will increase.
However, since carbon monoxide levels will also increase, and very little of that is needed to cause you harm, that’s the exhaust fume gas that you need to be most concerned about. It will start affecting you much before the carbon dioxide levels get to dangerous levels.
Particulate Matter in Exhaust Fumes
In addition to the gases, exhaust fumes also consist of tiny particles of dust suspended in the air, mainly soot.
Soot
What is soot?
Funnily enough, it’s tiny particles of carbon. Remember when we said that carbon burns to produce carbon dioxide or carbon monoxide, depending on how much oxygen was present?
Well, if there isn’t enough oxygen, and the fuel is burning at a lower temperature, some of the carbon atoms don’t combine with the oxygen at all and are instead dispersed in the form of soot.
Since these particles are very attracted to oily hydrocarbons, they generally settle down to form a greasy black coating on surfaces.
However, when inhaled, the particles are small enough to get inside your lungs and bloodstream. Once inside, they can affect your heart and lungs, leading to heart attacks, bronchitis, asthma, strokes, and more.
Vehicle Exhaust Fume Extraction
As you can see, working with vehicle exhaust fumes can be very hazardous. The HSE website recommends having a well-ventilated site combined with an exhaust gas scavenger system to keep the space free from lethal gases.
At VODEX, we offer a comprehensive range of automotive extraction products; including fume and dust extraction solutions for exhaust emissions in automobile workshops and garages.
Get in touch if you need help choosing the right extraction solution or if you need a bespoke product. With the help of our expertise and product range, you will be able to get a workplace that is free from all harmful gases and dust from vehicular exhaust emissions.
