Air fryers have earned their spot on the kitchen counter. They crisp up veggies, make better-for-you “fries,” and deliver that satisfying crunch without submerging your food in oil. For health-conscious cooks, they’ve become something of a kitchen hero.
But how often are you cleaning this beloved appliance? After every use? Once a month? Or maybe you’re just now reading this and realizing it’s yet to have happened.
New research suggests that a well-loved (but neglected) air fryer could be releasing more harmful compounds into your kitchen air than you’d expect.
What the research found
A study from the University of Birmingham1 set out to measure what air fryers actually release into your home. The researchers compared air frying to shallow frying and deep-fat frying, measuring volatile organic compounds (VOCs) and ultrafine particles—two types of emissions linked to health concerns.
The good news first: air frying is the healthier choice. It produces significantly fewer VOCs and ultrafine particles than traditional frying methods—we’re talking 10 to 100 times lower emissions than deep-fat frying, depending on the food.
But here’s where it gets interesting. When the researchers tested an air fryer that had been used more than 70 times without a deep clean, the emissions picture changed. That fryer released 23% more cooking-related VOCs and more than twice as many ultrafine particles compared to a clean one.
Oil residue and food particles build up in hard-to-reach spots inside the appliance. When you heat up the fryer again, those remnants essentially get re-cooked, releasing compounds into your kitchen air.
VOCs & ultrafine particles
Volatile organic compounds (VOCs) are gases released from certain materials and processes, including cooking. When oils and fats are heated, they can break down and release these compounds into the air. Research has linked indoor VOC exposure to respiratory symptoms, cardiovascular issues, and even certain cancers2. A systematic review of 69 studies3 found that high VOC levels were associated with upper airway symptoms, asthma, and cancer risk. Another randomized study4 found that VOC exposure was associated with systemic inflammation, oxidative stress, and elevated blood pressure.
Ultrafine particles (UFPs) are tiny particles—so small they can penetrate deep into your lungs and even enter your bloodstream. A 17-year study5 found that short-term UFP exposure triggered respiratory and cardiovascular hospital admissions, with the strongest links to COPD mortality and asthma. Research shows these particles are toxic to the respiratory, cardiovascular, and nervous systems6—they deposit deep in tissues, skip the body’s natural clearance mechanisms, and can even permeate cells.
But before you panic, the latest Birmingham study found that even the dirty air fryer’s emissions stayed below UK Government Buildings Regulations limits. We’re not talking about dangerous levels here. But if you’re using an air fryer specifically to be healthier, it makes sense to optimize the whole picture—including your indoor air quality.
Why cleaning matters more than you think
Think about what happens inside your air fryer over time. Tiny droplets of oil splatter onto the heating element and interior walls. Food particles find their way into crevices. That greasy film you might notice? It’s not just unsightly—it’s essentially fuel for future emissions.
Every time you preheat your air fryer, you’re reheating all that accumulated residue. The oils oxidize, break down, and release VOCs. The particles get aerosolized. And because air fryers work by circulating hot air at high speeds, those compounds get efficiently distributed throughout your kitchen.
The Birmingham researchers specifically noted that air fryer designs should allow for thorough deep cleaning—because clearly, it matters.
How to air fry the healthiest way
Here’s where we turn this research into action. A few simple habits can help you get all the benefits of air frying while minimizing any downsides:
Deep clean regularly. Don’t just wipe down the basket—get into the heating element area, the interior walls, and any crevices where grease accumulates. How often depends on how frequently you use it, but if you’re air frying several times a week, aim for a thorough deep clean at least monthly.
Choose an air fryer that’s easy to clean. When shopping for a new model, look for designs with removable, dishwasher-safe parts and accessible interiors. If you can’t easily reach all the surfaces, residue will inevitably build up. And don’t forget to avoid non-stick materials that could contain PFAS.
Opt for lower-fat foods. The study found that high-fat foods like frozen onion rings and bacon produced the highest emissions (though still far lower than deep frying). Vegetables, lean proteins, and foods with less added oil will generate fewer compounds overall.
Let it cool, then clean. Make it a habit to wipe down your air fryer after each use, once it’s cooled enough to handle safely. This prevents buildup from hardening and makes deep cleaning easier.
The takeaway
Air fryers are still a smart choice for health-conscious cooking. They genuinely do produce far fewer potentially harmful emissions than deep frying or even shallow frying. This research doesn’t change that.
What it does reveal is that maintenance matters. An air fryer that’s been loved but neglected can work against you in subtle ways—releasing more VOCs and ultrafine particles than a clean one would.
