Why Didn’t Anyone Smell Gas before the Explosion?

Your loved one is in a burn treatment center after being in a gas explosion. Before the explosion, no one smelled gas. You want to know if there should have been an odor and, if so, why there was not. 

Our job as your lawyers is to help you get answers.

Our lawyers are some of the very few in the nation who have won over $40 million for a client burned in an explosion. We can get these kinds of recoveries for our clients because we know the science needed to win cases.

Because of the complexity of these cases, winning a case requires an understanding of the science behind propane gas and something called odor fade. When we figure out what happened and why, we use this information to formulate a strategy for obtaining the best possible recovery for our clients, including a recent $45 million settlement.

Chemical Odorant Added to Natural Gas and Propane

Natural gas and propane are odorless, which means someone can be standing in a cloud of gas and not smell anything. Because any spark can ignite the gas, this would be an extremely dangerous situation.

This is why, as a safety feature, a chemical odorant is added to natural gas and liquid propane so that people can smell gas if there is a leak. The odorant provides a warning of a dangerous situation.

The odorant usually added to propane is called ethyl mercaptan. It smells like rotten eggs or a skunk. The odorant usually added to natural gas is called tetrahydrothiophene (THT). It smells like rotten cabbage.

If there is a gas leak, the smell is usually the first sign that there is a problem. In fact, it can be the only sign of a problem until a spark causes an explosion and fire.

What is Odor Fade?

Even if the correct amount of chemical odorant is added to the natural gas or liquid propane, certain conditions can cause the smell to dissipate. This is referred to as “odor fade.” If no one smelled gas before an explosion, one of the things we investigate is whether or not there was odor fade.

Odor fade is a common risk with new propane tanks. To reduce the risk of odor fade with new tanks, the propane company filling the tank for the first time must do the following:

1. purge the tank
2. fill the tank to the maximum level.

Companies are required to train their employees who fill these tanks to take these steps to prevent odor fade.

Gas Pipeline Leaks

A lot of pipelines in this country are very old—some are more than 100 years old. We are seeing more gas leaks involving these pipes. In some cases, no one smelled the gas or only smelled a hint of odor.

In these situations, we look for evidence of odor fade, which can happen when there is any kind of chemical change to the odorant that was added to the natural gas. For example, the chemicals in rust build-up in an old pipe can interact with the chemical odorant, modifying the odorant’s chemical composition enough to either reduce or eliminate the odor.

There can also be a problem with new sections of pipeline. A thin layer of odorant molecules can adhere to the lining of the new pipe, where chemical changes can happen as the odorant reacts to the lining chemicals. This is called adsorption, and it is a particular problem where there is intermittent or very little gas flow over a period of time. 

If there is a rupture of an underground pipeline, the odorant may be absorbed or oxidized as it travels through the soil. This is a particular problem in soils with a high clay content or with a high iron content.

Propane Leaks

Propane Tank Negligently Filled

Liquid propane odorant can react with chemicals in the lining of the tank if the tank is not filled to the right level or infrequently filled. When this happens, odor fade occurs.

For example, in one of our cases, the company responsible for filling the tank did not fill it with enough liquid propane to prevent odor fade. Propane gas leaked out and an invisible cloud of gas hung in the air by the deck of the house. When our client lit a match, the house blew up, burning him badly and catapulting him off of the deck, resulting in a traumatic brain injury.

It was our investigation that determined that the tank was not filled to the correct level, resulting in odor fade. Our inspection of the tank found that the brand new, 1000-gallon tank was filled with only 300 gallons of propane. 

A warning on the outside of the tank read:

“TO PROPANE GAS SERVICE REPRESENTATIVE: FILL THE TANK TO THE MAXIMUM ALLOWABLE LIQUID LEVEL AT THE TIME OF INSTALLATION OR IF THE TANK HAS BEEN OUT OF GAS, TO HELP REDUCE THE POSSIBILITY OF ODOR FADE.”

Attorneys Fred Pritzker and Eric Hageman won over $10 million for our client and his wife.

Underground Gas Leak

As with natural gas odorant, the odorant in propane can be absorbed into soil when there is an underground leak. These leaks can lead to gas build up in basements or other areas of a building. For example, in one incident, propane leaked from a cracked pipe that was damaged during excavation. A waterline was then installed above it, putting additional stress on the pipe, causing it to crack and leak. The investigation found that propane had migrated downhill underground and into the basement of a nearby building. When the gas ignited, several people died and others were severely injured.

Our job in cases like this is to find the cause and origin of the explosion. We then determine who was legally responsible, with a focus on what codes and rules were violated. With this information, we can formulate a plan for success in the courtroom.