Stinky Science

Pee-ew! People who live or work near a refinery may know it by the smell. Refineries are buildings where a material, like oil, is processed into different chemicals. People sometimes describe the odor as sour or rotten. But it doesn’t have to be that way.

“There are ways in which industrial odors can be reduced or even eliminated,” says Ned Ostojic. He’s an odor scientist based in Connecticut. When factory owners or their neighbors have a problem with an unwanted smell, they call in Ostojic to sniff it out and shut it down.

People often complain about odors like trash or sewage. But nice smells can be a problem too. Even the scent of freshly baked cookies can be annoying if it’s too strong or never goes away. Ostojic has investigated factories that make everything from cars to tea bags.

Pee-ew! Some people live or work near a refinery. They may know it by the smell. Refineries are facilities that turn a material, like oil, into different chemicals. People sometimes describe a refinery’s odor as sour or rotten. But it doesn’t have to be that way.

“There are ways in which industrial odors can be reduced or even eliminated,” says Ned Ostojic. He’s an odor scientist. He works in Connecticut. Sometimes factory owners or their neighbors notice unwanted smells. They call in Ostojic to sniff it out. Then he shuts the smell down.

People often complain about odors like trash or sewage. But nice smells can be a problem too. Even the scent of freshly baked cookies can be annoying. The smell can be too strong. Or it never goes away. Ostojic has inspected a lot of factories. They make everything from cars to tea bags.

Ostojic’s first goal at a stinky site is to find the source of the odor and measure it. This is especially difficult in refineries, where many potentially smelly processes take place. In one memorable case in California, Ostojic had to hunt down a bad smell in a refinery surrounded by other refineries!

To locate a smell, Ostojic needs to understand how odors travel. A smell starts when odor molecules are released into the air. These small particles of a substance carry its scent.

The molecules float through the air as an invisible, shapeless gas. Then they make their way into our noses (see How We Smell). There are millions of different molecules that can trigger our sense of smell.

Because smell is so complicated, it can be difficult to study. “No technology exists today that can measure odors nearly as well as our sense of smell,” says Ostojic. In other words, his most important tool is his nose!

Ostojic’s first goal at a stinky site is to find the cause of the odor. Then he measures the smell. This is tough to do in refineries. There are many smelly activities taking place. Ostojic once had to hunt down a bad smell in a refinery in California. It was hard to do because other refineries surrounded it. They each had their own smells.

Ostojic needs to know how odors travel to find a smell. A smell starts with odor molecules. They get freed into the air. These small particles of a substance carry its scent.

The molecules float through the air. They make up an invisible gas. Gas doesn’t have a shape. Then they make their way into our noses (see How We Smell). There are millions of different scent molecules. They can each set off our sense of smell.

Smell can be difficult to study. That’s because it’s so complex. “No technology exists today that can measure odors nearly as well as our sense of smell,” says Ostojic. That means his most important tool is his nose!

To measure an odor, scientists scoop up air samples in large bags made of thick plastic. They seal the bags quickly before the smells fade. Then the samples are mailed overnight to groups of trained smellers. These experts use their noses to judge the strength of smells. 

Measuring the odor in different parts of a building helps scientists determine where a smell is coming from. At the refinery in California, Ostojic found that two storage tanks were responsible for the stench.

After identifying an odor’s source, Ostojic makes a plan to get rid of it. Sometimes that means using a ventilation system to capture stinky air. Offensive molecules can then be burned or passed through filters. Goodbye, stink cloud! 

In California, Ostojic showed refinery workers which valve to close to stop the smell. But the solution at every site is different. “Detective work requires a fair amount of creative thinking,” says Ostojic. “It’s quite challenging, and it’s quite fun.”

Scientists have ways to measure odors. First, they scoop up air samples in large plastic bags. They seal the bags quickly. They don’t want the smells to fade. Then the samples are shipped overnight. They go to groups of trained smellers. They use their noses to judge the strength of odors.

Scientists measure the odor in different parts of a building. That helps them learn where a smell is coming from. Ostojic spotted two storage tanks at the refinery in California. They were causing the stench there.

Ostojic makes a plan to get rid of an odor after finding its source. Sometimes that means using a ventilation system. It can suck up stinky air. Smelly molecules can then be burned. Or they’re passed through filters. Goodbye, stink cloud!

Ostojic showed refinery workers a valve to close. It stopped the smell in the California refinery. But the solution at every site is different. “Detective work requires a fair amount of creative thinking,” says Ostojic. “It’s quite challenging, and it’s quite fun.”