Is Battery Corrosion Dangerous?

Flooded lead-acid battery corrosion is inevitable, but you can delay it with timely maintenance. Likewise, alkaline battery corrosion is common but preventable. In contrast, most AGM, gel, dry cell, and lithium batteries, whether ion or iron phosphate, don’t have external corrosion issues.

Battery corrosion is dangerous. The material build-up of lead-acid battery contains copper sulfate, an irritant, and a health & environmental hazard. Alkaline battery corrosion can cause exposure to potassium hydroxide, also an irritant and a hazardous substance.

Battery corrosion is dangerous to your health and the environment. Beyond the direct risks, you must be conscious of the implied dangers, such as the impact of a malfunctioning battery on the car, motorcycle, appliance, or device. Keep reading to avert the dangers of battery corrosion.

Battery corrosion is dangerous to your health and the environment.

Why Is Battery Corrosion Dangerous?

Battery corrosion is dangerous because it causes exposure to copper sulfate, aluminum sulfate, and sulfuric acid. Alkaline battery corrosion exposes you to potassium hydroxide and potassium carbonate. All these substances irritate the skin, eyes, lungs, and more.

The most common visible symptom of flooded lead-acid battery corrosion is material build-up on the clamps, cables, and cases around the terminals. This unpleasant substance may be white or a shade of blue and green. The white powdery substance is anhydrous copper sulfate. If you find a bluish-green mess, it’s still copper sulfate, but it has absorbed some moisture.

Copper Sulfate Is a Health and Environmental Hazard

The National Institutes of Health classifies copper sulfate as an irritant and environmental hazard.

The irritant is corrosive to human skin and can cause severe damage to the eyes. Furthermore, the National Library of Medicine document states that copper sulfate is toxic for aquatic life and an acute environmental hazard, with long-term adverse effects.

Aluminum Sulfate and Sulfuric Acid Can Harm Your Organs

The material build-up may not contain copper sulfate if you use aluminum clamps for your flooded lead-acid battery. However, aluminum is also vulnerable to sulfation. In effect, you’ll have aluminum sulfate, also an irritant that’s on the Special Health Hazard Substance List.

According to this New Jersey Department of Health datasheet, aluminum sulfate irritates the nose, throat, and lungs if inhaled, and you’ll experience coughing, wheezing, and breathing problems. The irritant causes skin rash upon contact and a burning feeling in the eyes. Ingesting aluminum sulfate affects the stomach and intestinal lining, causing vomiting, nausea, and diarrhea.

Furthermore, you shouldn’t try to wash aluminum sulfate away from your battery, whether the case or terminals and the cables or clamps. Aluminum sulfate mixed with water forms sulfuric acid, which can burn your skin and eyes. Also, the acid may damage your engine components.

Potassium Hydroxide and Potassium Carbonate Can Harm Your Eyes

The typical AA and AAA batteries use potassium hydroxide as the electrolyte. Thus, alkaline battery corrosion will have traces of potassium hydroxide through the leakage. The potassium hydroxide usually reacts with atmospheric carbon dioxide to form potassium carbonate.

Potassium carbonate is a stable compound, while not highly toxic, but is still an irritant. You should exercise caution, as any remaining potassium hydroxide is still harmful. Besides, you may have some rust or corrosion on the battery’s shell. Thus, you can’t be sure if it’s only potassium carbonate that you have to deal with or potassium hydroxide, too.  

Potassium hydroxide is extremely corrosive. It can cause burns on your eyes and skin. The compound can lead to severe damage to your eyes, irritation in your nose, throat, and lungs, and sustained exposure may cause pulmonary edema.

Also, potassium hydroxide causes skin allergy, and even limited exposure can induce vomiting, nausea, dizziness, and headache. Furthermore, potassium carbonate causes skin, eye, and respiratory irritation, depending on the medium and extent of your exposure to the substance.

Battery Corrosion Can Cause You to Get Stranded

In addition to the health hazards, you have to guard against the direct and implied dangers of battery corrosion. A failing battery in your car, van, or boat can leave you stranded.

Many automobile components relying on the battery will malfunction, and some may stop working altogether. Also, a few safety features won’t work if the electronics depend on the battery.

How Can I Protect Myself From Dangerous Battery Corrosion?

By wearing gloves, a mask, and eyewear, you can protect yourself from dangerous battery corrosion. Ensure you always wear these protective gear when inspecting, handling, and eliminating the chemicals. Also, exercise caution while washing flooded batteries to prevent accidental spillover.   

You may notice some signs of damage other than the evident symptoms of corrosion on a flooded lead-acid battery. Don’t proceed with your inspection or cleaning if you find a damaged case, swelling, or unusual sulfuric acid and water spills.

Likewise, wear protective gear when you handle corroded AA or AAA batteries. It’s normal for most people not to consider these small batteries as a significant threat. However, you should guard against substantial potassium hydroxide and potassium carbonate exposure.

How Can I Clean Battery Corrosion?

You can use a flooded lead-acid battery cleaner to clean battery corrosion. Doing this will neutralize and remove the chemical build-up. Alternatively, you can use baking soda, water, and a cleaning brush with stiff bristles. If AA or AAA alkaline batteries are corroded, do remove them safely.

Always power off the connected systems, whether the car or onboard components. Disconnect the battery before inspecting or cleaning it. Also, disconnect the negative terminal first and then the positive. After cleaning, connect the positive terminal before the negative. Ideally, you should remove a flooded lead-acid battery from your car, van, or boat before cleaning the corrosion.

You might also want to read: How to Clean Battery Corrosion in Toys

How Can I Prevent Flooded Lead-Acid Battery Corrosion?

You can prevent flooded lead-acid battery corrosion by avoiding overcharging and undercharging your battery. Maintain the battery well, use grease on the terminals, and store it with sufficient charge. For alkaline batteries, remove them from the devices when not in use.

Overcharging a flooded lead-acid battery facilitates corrosion on the positive terminal. Likewise, undercharging can cause corrosion on the negative terminal. Also, don’t add water beyond the maximum threshold for a flooded lead-acid battery, as that’ll make it vulnerable to spills.


Any type of battery corrosion is dangerous if you find a chemical build-up outside on the case. Internal battery corrosion isn’t always evident, and the sealed variants don’t have the typical leakage or spillage problem. Thus, always exercise caution and seek assistance if necessary.

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