What’s So Bad About Bringing Smelly Food Onboard My Flight?

In this month’s “Dear Eugene,” we ask experts why bringing smelly food onboard a flight, such as that tuna fish sandwich you bought inside the terminal, is an etiquette faux pas.

Inspired by our intrepid founder, Eugene Fodor, Dear Eugene is a monthly series in which we invite readers to ask us their top travel questions. Each month, we’ll tap travel experts to answer your questions with the hopes of demystifying the more complicated parts of travel. Send your questions to [email protected] for a chance to have them answered in a future story.

Dear Eugene, I was running to catch a flight and, starving, picked up a tuna fish sandwich from one of the restaurants in the terminal. Once settled in my seat, it became very clear that the passengers around me were not happy with my onboard meal, making it a point to wrinkle their noses in disgust and openly glare at me. I feel it’s my right as a paying passenger to eat whatever I want onboard, but maybe I’m wrong. When it comes to flying, should I care about bringing smelly food onboard? 

You are indeed a paying customer, and technically, your plane ticket doesn’t come with a ban on airport food. But flying is governed by a set of unspoken etiquette rules, and not all of them are obvious.

Some are practical, like waiting your turn to disembark row by row. Others fall under the umbrella of social courtesy, such as returning your seat to the upright position during meal service so the person behind you has space to eat. Your tuna sandwich, dear reader, violated the latter. Although you didn’t intend to be inconsiderate, your meal choice was judged that way by those around you.

“Any time we are in a public setting—let alone a confined one such as an airplane cabin with poor airflow—it’s vitally important we consider how our choices and actions affect the comfort and sensibility of others,” explains etiquette expert Thomas P. Farley, aka Mister Manners. “There are innumerable items that could be brought aboard a plane that are odor-free. A tuna fish sandwich is definitely not one of them.”

Why Is The Smell of Fish so Offensive to Some?

Your fellow passengers might be fans of the humble tuna fish sandwich under normal circumstances, but being in forced proximity to one at 30,000 feet is entirely different. After all, our noses are famously sensitive to trimethylamine (TMA)—the compound responsible for that “fishy” smell. We’re biologically wired to sniff out even small amounts of TMA, which intensifies as fish rots, to prevent us from consuming anything that might make us sick.

“The smell of fish is generally less tolerated the stronger it is, and we are very good at detecting fish scent at low concentrations,” explains Dr. Rachel Herz, a neuroscientist and expert in the psychological science of scent and the author of Why You Eat What You Eat. “The scent is even stronger to fellow passengers on a plane because of limited airflow in the tight and crowded space, so you would smell the tuna sandwich more on a plane than in the airport lounge, for example.”

Of course, food smells are culturally relative, but the lack of control is key here. “As an analogy, it’s sort of like someone draping their coat on you instead of keeping it in their own seat,” says Dr. Hertz. “Unfortunately, when it comes to shared air on a plane, it is nearly impossible not to be touched by the proverbial coat, e.g., the scent of a tuna sandwich for those nearby.”

How to Pick a Kinder-on-the-Nose Option

If you don’t want to be called out on Passenger Shaming (an Instagram account dedicated to in-flight faux pas), we recommend choosing a more under-the-olfactory-radar option next time.

“As a rule, any food brought onto a plane should ideally be odor-neutral, neat, and non-noisy,” Farley says. Steer clear of anything ultra-fragrant, like curries, eggs, or greasy takeout meals. Instead, try a soft granola bar, banana, or a veggie wrap, Farley suggests.

When Dr. Hertz flies, she opts for a cold cheese and tomato sandwich.

“Interestingly, cheese, tomato, and bread are high in umami (savory taste), and the taste of umami is heightened on airplanes due to how the ambient noise of aircraft affects the cranial nerves that are involved in both hearing and taste.”

Thus, the sandwich is actually more delicious during a flight than in the airport lounge. It’s a win-win: not smelly for other passengers and more delicious for you.