Why You Don’t Always Smell Gas Before an Explosion

The rotten egg smell most of us associate with natural gas is an additive meant to function as a warning: If you smell it, there is a problem. But sometimes there’s a problem – a life-threatening one, when you don’t smell a thing. Here are four reasons why:

The Gas Leak Occurred Before Odorant Was Added

Natural gas is odorless and colorless, and for a significant portion of its journey from the wellhead to the consumer, it remains that way. From wells, natural gas travels through gathering lines that lead to transmission lines headed for processing plants, storage facilities and compressor stations before it reaches a city gate station where an odorant, such as mercaptan, is added. From there, it moves through distribution lines to commercial and residential consumers. (Note: In some states, such as California, odorant is added to gas in underground storage areas. In other states, such as Michigan, it is not. See more below.)

If a line is cut anywhere along the way to the gate where odorant is added, gas will leak without odor creating a dangerous situation that can end in tragedy. That’s exactly what happened in Firestone, CO on April 17 when a home explosion killed two people and badly injured a third.

Firestone Home Explosion

An abandoned pipeline running from a well near the house owned by Erin and Mark Martinez had been cut before the Oak Meadows subdivision was built by Denver-based Century Communities in 2015. The odorless gas seeped into the ground and then into the house through French drains and a sump pump pit, investigators announced this week.
The explosion killed Mark and his brother-in-law, Joseph (Joey) William Irwin III. Erin was severely injured and remains hospitalized in critical condition. A construction crew working in the area rescued Erin by using a forklift to lift a portion of the collapsed house that had pinned her so they could pull her to safety. The massive fire that followed the blast destroyed the home within 15 minutes, witnesses told local media.

The explosion killed Mark and his brother-in-law, Joseph (Joey) William Irwin III. Erin was severely injured and remains hospitalized in critical condition. A construction crew working in the area rescued Erin by using a forklift to lift a portion of the collapsed house that had pinned her so they could pull her to safety. The massive fire that followed the blast destroyed the home within 15 minutes, witnesses told local media.

The 24-year-old well was not built by but is currently operated by Anadarko Petroleum Corporation based in Woodlands, TX. The company has temporarily closed the well and 3,000 others in northeastern Colorado in the wake of the explosion.

Over the last two weeks, there has been an outpouring of support from the community which has contributed more than $100,000 to the GoFundMe page set up for the families. And, with the aim of preventing future tragedies, Colorado Governor John Hickenlooper has ordered a statewide review of existing oil and gas operations including inspections and testing of existing flowlines within 1,000 feet of occupied buildings.

Factors that Inhibit Our Sense of Smell

Another reason why some people don’t smell gas before an explosion is that something has affected their sense of smell. Several factors including age, smoking and general health can inhibit our sense of smell. As we age, we tend to lose our sense of smell. Most people over the age of 60 have a decreased sense of smell, as do smokers, and people with head colds, sinus infections, allergies or nerve damage from head trauma.

After prolonged exposure, some people can develop “odor fatigue” and stop noticing the bad smell. This was not the case for the people in the Porter Ranch, California or Eight Mile, Alabama who were overwhelmed by the smell of odorant and suffered health problems.

The Aliso Canyon underground storage facility gas leak near Porter Ranch, California, considered the worst natural gas leak in U.S. history, spewed roughly 100,000 metric tons of methane into the surrounding area over a four-month period before it was sealed on February 11, 2016.

Southern California Gas Co. owns the Aliso Canyon -the largest gas storage facility west of the Mississippi River and second-largest in the nation. During and after the leak, residents of Porter Ranch experienced headaches, nausea, rashes and nosebleeds. They were relocated. Residents of Eight Mile, AL haven’t been as lucky.

A lightning strike at a natural gas facility ruptured a mercaptan storage tank there nine years ago spilling an estimated 500 gallons of the chemical into the soil and groundwater. Not long after, residents of the community began to experience health problems including respiratory issues, headaches, nausea, rashes and nosebleeds. Mobile Gas Service Corp., which owned the facility at the time of the spill, said it hired companies to clean it up, and they failed. The rotten egg smell of the mercaptan still hangs in the air as reports of health issues mount.

Michigan has more underground natural gas storage reservoirs than any other state in the country, many of them similar to Aliso Canyon’s, construction and vintage though not large. But there’s one big difference. The gas in Michigan’s storage fields isn’t odorized. If a leak happens or is happening there, it could be a challenge to discover.

Masking

Some companies use another chemical to cover up the rotten egg smell while they clean up small spills or perform maintenance on equipment. “Anecdotal descriptions of masking events in the natural gas industry have persisted for over a decade, with the frequency of such events on the rise,” according to a 2011 joint study by the National Institute of Standards and technology and the American Gas Association.

Odor Fade

Certain conditions can cause the smell of the odorant to diminish to the point where it can’t be detected. This is called “odor fade” and it occurs through the process of adsorption, absorption, and oxidation.

Adsorption is when the molecules of the odorant stick to the interior of the pipe and are, therefore, no longer in the stream of gas. This happens most frequently with new pipe installations. Absorption is when odorant molecules are absorbed into the gas and are no longer detectable. And oxidation happens when the odorant is exposed to rust or air and the change in its chemical structure results in loss of odor. Pipeline conditions (more than 60 percent of them were built before 1970 and some are 100 years old or more) and quality of gas are contributing factors to oxidation.

Pritzker Hageman represents people who have been injured and families who have lost loved ones in explosions. For one client who was severely burned, we recently secured a $10 million settlement. Our lead lawyers for these cases are Fred Pritzker and Eric Hageman, Contact them by calling 1 (888) 377-8900 (toll-free) or clicking here. The consultation is free and there is no obligation.

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Category: Explosion, Fire and Burn Injuries
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