Is Benzene Flammable?

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Benzene is one of the most heavily manufactured chemicals in the world, making it into the Top 20 most produced chemicals in the United States. Yet, it’s not exactly a household name, despite being used in detergents, explosives, pesticides, plastics, and a plethora of other chemicals. But is this something we need to worry about? Is benzene flammable and does it have any impact on our health? 

Benzene is highly flammable and has a flashpoint of -11 degrees Celsius (12.2 Fahrenheit) which means it will ignite easily in most ambient temperatures.

Fortunately, most of us don’t store liquid benzene around our homes, but that doesn’t mean we shouldn’t pay careful attention to benzene, here’s why. 

Also read: What Makes Something Flammable?

About Benzene

Benzene is an unusual chemical compound. 

It has the chemical formula C6H6 but what makes it interesting is that the carbon atoms are all joined in a hexagonal ring and each hydrogen is attached to an individual carbon atom. 

At room temperature benzene is a liquid and it has no color and a strong sweet smell to it. 

Its most important use is as a precursor chemical in complex chemical reactions and billions of kilos of benzene are put to use in industry every year. 

It is extracted from crude oil during the standard fractionating process performed on oil to extract each of its constituent parts and is, thus, a petrochemical. 

Benzene can be found in various other oils including “gum benzoin” (a resin from Southwest Asia) and Coal Tar. 

What Is Benzene | Organic Chemistry | Chemistry | FuseSchool

Is Benzene Flammable? (Flashpoint)

Benzene is a highly flammable liquid that burns very easily at relatively low temperatures. This is the criteria OSHA uses for determining the flammability of liquids.

The flashpoint of benzene is 11.07 degrees Fahrenheit or -11.63 degrees Celsius and thus Benzene is above its flashpoint at room temperature or even storage temperatures in most of the world. 

The good news is that it won’t spontaneously combust until it reaches much higher temperatures. The autoignition point of benzene is 928 degrees Fahrenheit or 497.78 degrees Celsius. 

Also read: Is Freon® Flammable?

Hazards of Benzene

Despite the widespread use of benzene in products that all of us use, benzene is, in fact, a very hazardous chemical and the effects of exposure can be very harmful, indeed.

Is It Poisonous?

Benzene is potentially very harmful to human health. 

On first exposure to the skin, eyes, or inhalation, it is considered to be an irritant of moderate to severe strength. 

On the skin, it burns and causes swelling and redness. In the eyes, it will make someone cry, and leave them with sore, red eyes. 

When you inhale it, it can cause irritation (including coughing) of your nose and throat. It can damage your nervous system and cause nausea, confusion, headaches, dizziness, and lethargy, or exhaustion. In severe cases, it can make you pass out. 

It’s no better if you are foolish enough to eat benzene and not only can this cause similar problems as inhaling benzene does it can also get drawn into your lungs and severely damage them. This can cause death. 

In fact, benzene is considered to be very toxic in long-term exposure and it can damage the blood cells and the immune system. There is also some marginal data that shows it may also damage the nervous system permanently, however, as it’s unethical to conduct human trials on this, there is not enough data to show this for certain. 

And, in addition to being toxic, benzene is a known carcinogen and, in particular, long-term exposure to benzene can result in cancers of the blood. 

It is also a mutagen which is a compound that can cause genetic damage and if a potential parent is exposed to benzene in the long-term, their child may be born with genetic damage. 

What Happens to Benzene in the Body?

Can It Be Absorbed Through The Skin? 

Yes, benzene can be absorbed through the skin, though official advice says this is unlikely to be damaging and that the most negative effects of benzene are caused by inhalation or consumption. 

We think that given the insufficiency of data on this subject, you’d be better off wearing gloves and protective clothing (and they should be capable of resisting organic solvents) when handling benzene just to be on the safe side. 

What Should You Do If You’re Exposed To Benzene?

It depends on how you’re exposed:

  • If someone inhales benzene – remove any possible sources of ignition and ensure your own safety prior to intervening. Then move them into fresh air. Then get immediate medical attention.
  • If someone spills it on themselves – remove any clothing on the affected areas and then flush with water for up to 20 minutes. If there is any irritation or pain after this, get medical help. Double bag the clothing, label it properly and then leave them for safe disposal.
  • If someone gets it in their eyes – hold their eyelids open and flush them for 20 minutes with gentle flowing water. Do not remove any contact lenses. If there is any irritation or pain after rinsing seek medical attention. 
  • If someone drinks/eat it – rinse their mouth with water. If they vomit, get them to lean forward as this can help prevent it from ending up in their lungs. Get them to rinses their mouth each time they vomit. Call a doctor or a poison center. 

How Long Does It Stay In Your System? 

Your body breaks down benzene over a period of roughly 48 hours, after which the majority of metabolites are expelled by excretion. However, any damage done to your body during this period is not undone by excretion. 

How Do You Dispose Of Benzene In A Lab?

If you are unlucky enough to spill benzene in a lab or workplace situation, it is important that you deal with it appropriately. 

Because benzene is both poisonous and highly flammable, the first thing to do is to absorb the benzene rather than try and wash it away.

So, you scatter dry earth or dry sand over the chemical to soak it up. The earth should then be disposed of appropriately following the substance disposal protocols in place in the workplace.

Finally, the area where the benzene was should be sluiced with large amounts of water to remove any traces. 

If you just use water to flush benzene from a space, there is a serious danger of explosion in the sewers that take the water away. 

Where Is It Found In The Workplace?

As we noted at the start of this piece, benzene is usually used in complex chemical processes, and coal products, petroleum products, dyes, rubber, plastics, lubricants, and other chemical products may all be made with benzene. 

This means it can be very difficult to predict where you might encounter benzene in the workplace. 

It also explains why it’s so important to check material safety sheets when working with chemical products in the workplace, they will help you identify any potential hazards and mitigate them effectively, including benzene. 

At What Level Can You Smell Benzene?

You can smell benzene at between 1.5 – 4.7 parts per million in the air, this is above the level deemed as safe for everyday exposure but is not so hazardous that you are at serious risk of harm. 

This means that smell is often a great way to determine that there is exposure to benzene and to take preventative measures before things get worse. 

How Much Is Safe? 

OSHA, according to Cancer.org, has determined that the maximum exposure that should be allowed in a workplace must be limited to an average of 1 part per million in the air during an average workday.

They also say that there should be a maximum exposure of 5 parts per million for 15 minutes. 

If your work environment presents a higher risk of benzene exposure, protective equipment must be supplied. 

How Much Is In A Cigarette?

Smoking is bad. 

Not only does it lead to diseases that kill 1 in 3 smokers, but smoking also results in a great number of fires that put other people’s lives at risk. 

It’s also a great way to pipe poisonous benzene into your body. 

A cigarette can contain as much as 80 micrograms of benzene, which doesn’t sound like a lot. 

But it means that a 40 a day smoker is breathing in up to 3 milligrams of benzene a day and this may explain why smokers have a much higher rate of leukemia than the population at large. 

Sources

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