Can Asthma Inhalers Explode or Catch Fire? Safety Explained

Feb 02, 2018 Asthma

Asthma inhalers are lifesaving devices that millions of people in the UK carry every day. As most relievers and preventers are aerosol-based, people sometimes worry about their stability. Since they are pressurised containers, it is important to understand the specific conditions under which they could become a hazard. While inhalers rarely explode, it’s important to make sure your inhaler is safe and that the quality of the medication remains high. 

Are Asthma Inhalers Flammable?

Most modern metered dose inhalers (MDIs) use a propellant called hydrofluoroalkane (HFA). Unlike older inhalers that used chlorofluorocarbons (CFCs) or common household aerosols like hairspray and deodorant, HFA propellants are generally non-flammable.

However, while the propellant itself may not ignite, the medication inside is stored under high pressure. If the canister is exposed to an open flame or extreme heat, the integrity of the metal can be compromised. For this reason, you should never throw an empty inhaler into a fire or store it near a heat source.

Can Asthma Inhalers Explode?

Yes, like any pressurised aerosol canister, an asthma inhaler has the potential to burst or explode if subjected to extreme pressure or temperature changes. The metal canister is designed to hold the gas safely at room temperature, but as the temperature rises, the pressure inside the canister increases.

If the internal pressure exceeds the strength of the aluminium container, it will rupture. This is not a spontaneous chemical explosion but rather a mechanical failure of the canister due to heat expansion.

What Happens If an Inhaler Gets Too Hot?

Leaving an inhaler in a hot car, on a sunny windowsill, or near a radiator can be dangerous for two reasons:

1. Risk of Bursting: In a closed vehicle on a hot summer day, temperatures can quickly exceed the safety limit of the canister (usually around 50°C), leading to a risk of the canister bursting.
2. Reduced Effectiveness: Extreme heat can change the chemical composition of the medication, such as Salbutamol. If the inhaler gets too hot, the dose delivered may not be effective during an asthma attack, which poses a significant health risk.

If your inhaler feels very hot to the touch, it is best to consult a pharmacist to ensure the medication is still safe to use.

Can You Take an Asthma Inhaler on a Plane?

You can absolutely take your asthma inhaler on a plane. In fact, it is highly recommended that you keep your inhaler in your hand luggage rather than in the hold. This ensures you have immediate access to it if the cabin air triggers your asthma.

Airlines and airport security consider inhalers to be essential medical items. Because the volume of medication in a standard canister is well below the usual 100ml liquid limit, they are easily cleared through security. The pressure changes in a plane cabin are regulated and are not significant enough to cause an inhaler to leak or explode.

How to Use and Store Your Inhaler Safely

To ensure your treatment remains effective and your device remains safe, follow these storage guidelines:

• Store in a cool, dry place: Keep your inhaler at room temperature (ideally between 15°C and 25°C).
• Keep the cap on: This prevents lint and debris from entering the mouthpiece and blocking the valve.
• Avoid direct sunlight: Do not leave your inhaler in direct sunlight or in a vehicle.
• Dispose of safely: Do not puncture or burn the canister even when it is empty. Take expired or empty inhalers to a local pharmacy for safe disposal.

As Simply Meds Online is a registered UK pharmacy, we can offer emergency prescriptions, including asthma inhalers, if you forget yours or have to discard it because it is damaged.

For more information on different types of inhalers and their care, visit the Asthma and Lung UK site.

 

Frequently Asked Questions (FAQ)

Can I leave my inhaler in the car during the summer?

It is not recommended. On a hot day, temperatures inside a parked car can quickly exceed 50°C, even in the UK, which is the standard safety limit for most pressurised canisters. This level of heat can cause the canister to burst or cause the medication to degrade, making it less effective when you need it most.

What should I do if my inhaler accidentally gets very hot?

If your inhaler has been exposed to extreme heat (such as being left on a radiator or in the sun), do not use it. The heat may have altered the drug's molecular structure. Contact your pharmacist for advice. They will likely recommend replacing it to ensure you have a reliable dose in an emergency.

Is it safe to put an empty inhaler in the bin?

No. You should never dispose of an inhaler in your household waste or recycling bin. Even empty canisters contain residual pressure and can explode if crushed in a bin lorry or exposed to heat at a waste facility. Instead, take your used inhalers to a local pharmacy, where they can be disposed of safely and through environmentally friendly medical waste channels.

Do inhalers expire, and are they dangerous after that date?

Inhalers generally have an expiry date of one to two years from the date of manufacture. While an expired inhaler is unlikely to explode, the medication inside loses its potency over time. Relying on an expired "reliever" during an asthma attack is dangerous because it may not provide the necessary relief when you need it.

Can an inhaler explode if it is dropped?

While inhaler canisters are made of durable aluminium, a significant impact (like being dropped from a height or hit with a heavy object) could dent the metal or damage the valve. A dented canister is structurally weaker and more prone to leaking or bursting if later exposed to heat. If the canister is visibly deformed, it is best to replace it.

Are dry powder inhalers (DPIs) safer than aerosol ones?

Dry powder inhalers (like Accuhalers or Turbohalers) are not pressurised and do not contain liquid propellants, so they do not carry the same "explosion" risk as metered-dose inhalers (MDIs). However, they are extremely sensitive to moisture and humidity, which can cause the powder to clump and become unusable. Both types require careful storage to remain effective.