I Washed My Inhaler—Can I Still Use It?

Whether a washed inhaler is safe to use depends entirely on which type of inhaler you have and which part got wet. If you rinsed the plastic mouthpiece of a pressurized metered-dose inhaler (the kind with a metal canister you press down), that’s not only fine but actually recommended at least once a week. If water got into a dry powder inhaler or soaked the metal canister of an MDI, the situation is more complicated and potentially means you need a replacement.

MDI Mouthpiece Cleaning Is Something You Should Already Be Doing

If you use a standard pressurized inhaler with an HFA propellant, the kind most people picture when they think of an asthma inhaler, the plastic housing (called the actuator) is designed to be washed. Manufacturer guidelines for HFA inhalers recommend washing the actuator with warm water at least once a week to ensure correct dosing and to prevent the tiny spray orifice from getting clogged with dried medication residue.¹ So if you ran the plastic part under the tap, you did exactly what you were supposed to do.

The proper method is straightforward: pull the metal canister out of the plastic actuator, run warm water through the mouthpiece for about 30 seconds, shake off excess water, and let it air dry completely (usually overnight) before reinserting the canister. You should never put the metal canister itself under water or submerge it. The canister contains the pressurized drug-propellant mixture and has a metering valve at its base. Water in or around that valve can interfere with how precisely each puff is measured, and moisture inside the canister could degrade the formulation.

What If the Metal Canister Got Wet

If you accidentally submerged the whole inhaler, canister and all, in water or ran the assembled unit through a washing machine, the stakes are different. The metal canister is sealed, so a brief splash on the outside is unlikely to cause problems. Dry the outside thoroughly and reinsert it into a clean, dry actuator. But if the canister sat in water for an extended period, water could have wicked into the metering valve assembly or compromised the seal around the valve stem. A compromised seal can cause the propellant to leak faster than normal, which means you might get fewer usable doses than the counter says you have left.

Research on HFA albuterol inhalers exposed to extreme environmental conditions found that stressed inhalers showed a modest increase in propellant leak rate, though the particle size and respirable dose per actuation remained relatively stable under some conditions.² That study looked at temperature extremes rather than water immersion, but the principle about seal integrity applies: anything that stresses the canister’s sealing system can accelerate propellant loss. If the canister was fully submerged for more than a few seconds, the cautious move is to call your pharmacy and get a replacement, especially if this is a rescue inhaler you depend on during an asthma attack.

Dry Powder Inhalers Are a Different Story Entirely

Dry powder inhalers like the Diskus, Ellipta, Turbuhaler, and HandiHaler work on a fundamentally different principle from pressurized MDIs. There’s no propellant pushing the drug out. Instead, you inhale forcefully and your breath pulls a finely milled powder into your lungs. The drug particles are typically blended with a lactose carrier, and the force of your inhalation separates the drug from the carrier so the tiny drug particles can reach deep into your airways. This entire system depends on the powder staying dry.

If you washed a dry powder inhaler or got water inside the device, the powder is almost certainly compromised. Even exposure to elevated humidity, well short of direct water contact, has been shown to damage DPI formulations. Research has found that when drug-carrier blends in DPIs are exposed to rising humidity, the adhesion between drug particles and lactose carrier increases significantly with each step up in moisture level. Capillary forces between the particles grow stronger in humid conditions, which means the drug clings more tightly to the carrier and resists being pulled apart by your breath.³ The practical result: less medication reaches your lungs with each inhalation.

The problem goes deeper than just clumping. The lactose carrier particles in DPI formulations are carefully manufactured to have a high degree of crystallinity, meaning a very orderly molecular structure. When moisture contacts the particle surfaces, any amorphous (disordered) regions start to recrystallize, changing the surface characteristics and making the drug-carrier interaction unpredictable. This recrystallization process can begin at surprisingly low humidity levels, potentially as low as 35% relative humidity at room temperature.⁴ Direct water contact would accelerate this process dramatically. If your DPI got washed or even just very wet inside, the powder is no longer reliable and the inhaler should be replaced.

Not All DPIs Are Equally Fragile

Different DPI designs offer different degrees of protection against moisture. Some devices store each dose in a sealed blister or capsule that isn’t exposed to the air until the moment you use it. The Diskus, for example, peels open individual foil blisters with each dose. The HandiHaler uses individually packaged capsules you load one at a time. These designs offer a layer of moisture protection: even if the device housing gets damp, the sealed doses inside may remain unaffected as long as the foil or capsule wasn’t breached.

Other DPI designs, like the Turbuhaler, store the drug in a bulk reservoir inside the device. With reservoir-type inhalers, the entire drug supply is exposed to whatever conditions exist inside the device housing. If water entered a reservoir-type DPI, every remaining dose is likely compromised. In-vitro testing of various DPIs has confirmed that reservoir-type devices tend to show greater sensitivity to humidity than blister-based designs, precisely because the powder has less barrier protection.⁴

If you washed a blister-based DPI and the external housing got wet but you didn’t force water into the blister mechanism, you may be able to dry the device thoroughly and continue using it. But if water clearly entered the drug compartment or you can see moisture on the powder, replace it. When you’re dealing with medication that controls your breathing, “probably fine” is not a standard worth accepting.

Nebulizer Parts Are Meant to Be Washed

If your question is about a nebulizer rather than a handheld inhaler, the answer flips completely. Nebulizer components, including the medication cup, mask or mouthpiece, tubing, and T-piece, should be washed after every use. The liquid medication sits in a reservoir and gets aerosolized by compressed air or ultrasonic vibration, which means the parts are already wet during normal operation. Failing to clean them invites bacterial growth in residual moisture and medication residue.

Despite this being standard guidance, most nebulizer users don’t follow it. A study of home nebulizer practices among COPD patients found that the majority did not wash parts in warm soapy water after each use, and nearly all never disinfected their nebulizer components.⁵ This is a genuine infection risk. Nebulizer reservoirs and tubing can harbor Pseudomonas and other bacteria that are especially dangerous for people with compromised lungs. So if you washed your nebulizer parts, you made the right call, and you should keep doing it.

The standard cleaning routine for nebulizers involves rinsing all parts (except the compressor) in warm soapy water after each treatment session, then rinsing with clean water and allowing everything to air dry on a clean towel. Once or twice a week, parts should be soaked in a dilute vinegar solution or disinfected according to the manufacturer’s instructions. Replace the nebulizer cup, mask, and tubing on a regular schedule, typically every three to six months depending on how often you use it.

How to Tell If Your Inhaler Still Delivers a Proper Dose

After any accidental washing or water exposure, test before you trust. For an MDI, reinsert the canister into the dry actuator and fire a test puff into the air (away from your face). You should see a fine, even mist. If the spray comes out as a weak stream, sputters, or shoots off to one side, the actuator orifice may still be clogged with water, or the canister valve may have been affected. Try shaking the canister vigorously, drying everything again, and testing once more. If it still doesn’t spray normally, get a replacement.

For a DPI, there’s no visible spray to check, which makes assessment harder. If you can open the device and see the powder, look for signs of caking or clumping. Powder that has absorbed moisture often looks slightly darker or feels gritty rather than silky. Some DPIs let you hear or feel the powder when you rotate the dose mechanism; if the device feels or sounds different than usual (grating, sticky, or sluggish), that’s a warning sign. The more honest test is simply whether you can feel the medication in your throat when you inhale a dose. If it feels like you’re inhaling nothing, the drug likely isn’t being dispersed properly.

Neither of these checks replaces getting a new device if you have serious doubts. An inhaler that delivers a partial dose is arguably worse than having no inhaler at all, because it gives you false confidence that you’re being treated when you’re actually under-dosed. This is especially true for controller medications like inhaled corticosteroids, where consistent dosing prevents flare-ups you won’t feel until it’s too late.

The Washing Machine and Laundry Scenario

One of the most common ways people end up with a washed inhaler is forgetting it in a pocket before running laundry. This subjects the device to prolonged water submersion, detergent, mechanical tumbling, and often heat from the dryer afterward. For an MDI, the plastic actuator may survive the wash but the detergent residue is a concern. Soap residue left in the mouthpiece could irritate your airways when you inhale through it. If the actuator went through the wash, rinse it extremely thoroughly with clean water, let it dry fully, and inspect it for cracks or warping. If the canister also went through, the sustained water exposure and heat make replacement the safest option.

For a DPI that went through a full wash cycle, the device is done. There’s no salvaging a dry powder formulation after that kind of moisture exposure. Even if the external housing seems intact, the powder inside has been exposed to conditions far beyond what the formulation was designed to withstand. Replace it. If you can’t get a prescription refill immediately, contact your prescriber’s office and explain what happened. Most will authorize an early refill or call in a replacement, since going without an inhaler carries real risk.

If the inhaler also went through a dryer cycle, heat adds another variable. The temperatures inside a clothes dryer can exceed what many inhaler components are rated for. Plastic housings can warp subtly enough that you don’t notice visually but enough that the metering mechanism doesn’t seat properly. For MDI canisters, elevated temperatures increase propellant pressure and can affect the valve seal, leading to dose inconsistency even if the canister looks normal.²

Preventing the Problem in the First Place

The most effective strategy is to store your inhaler in the same place every time you use it, rather than pocketing it and forgetting it there. A designated spot on a nightstand, in a bag, or in a medicine cabinet means the inhaler never ends up in the wash. If you do carry an inhaler in a pocket or bag, consider a small protective case. Cases designed for inhalers aren’t expensive, and they add a visual and tactile reminder to check your pockets before doing laundry.

For DPIs in particular, general moisture protection matters even outside of a washing accident. Store DPIs away from bathrooms and kitchens where ambient humidity runs high. Some DPI manufacturers include desiccant packets in the packaging. Those packets aren’t decoration; they’re there because even ambient moisture affects the powder formulation over time. Keep the inhaler in its sealed pouch until you’re ready to start using it, and close the device’s mouthpiece cover between uses if it has one.

For MDIs, the weekly actuator wash is one of the most neglected maintenance steps. Medication residue builds up around the spray orifice gradually, and you may not notice a reduction in spray quality until the opening is substantially blocked. Setting a recurring reminder to clean the actuator on the same day each week takes the guesswork out of it. Rinse, shake, dry overnight, and reassemble in the morning. Your lungs will get more consistent medication delivery, and you’ll avoid the irony of an inhaler that stops working because it was never cleaned in the first place.

Soft Mist Inhalers

One inhaler type that doesn’t fit neatly into either the MDI or DPI category is the soft mist inhaler, such as the Respimat. These devices use a spring-loaded mechanism to push a liquid drug solution through a tiny nozzle, creating a slow-moving aerosol cloud. The medication is stored as a liquid in a cartridge, so the device already involves fluid. However, the cartridge is sealed and the nozzle assembly is precision-engineered. Getting water inside the nozzle or spring mechanism can interfere with the device’s function.

For a Respimat-type device, the mouthpiece can be wiped with a clean, damp cloth, but the device shouldn’t be submerged or run under a faucet. If the internal mechanism got wet, the spring and dosing system may not operate correctly. You can try actuating the device a few times to see if it produces its characteristic slow mist. If it sputters, drips, or doesn’t fire at all, the mechanism likely needs replacing. Because the cartridge holds liquid medication in a sealed system, a brief external splash is less concerning than with a DPI, but internal water intrusion is still a problem for the mechanical components.