How To Neutralize Battery Acid and Clean Up Battery Acid Spills
Battery acid and battery electrolytes, in general, are chemicals that should not come in contact with skin, clothes, and other everyday materials.
Also, their vapors and fumes can be rather dangerous - when battery electrolytes come in contact with other materials, they can react in unpredictable ways creating perhaps even more dangerous compounds.
When a battery starts to leak, the battery acid must be neutralized, and the battery must be considered as dangerous and must be replaced and properly recycled.
Published: October 19, 2022.
Fortunately, smaller battery spills can be cleaned up using common household items like baking soda, vinegar, lemon juice, and similar. However, to neutralize larger amounts of battery acids, one needs professional products.
How To Neutralize Lead-Acid Battery Acid
Although AGM and Gel-Cell lead-acid batteries are rather popular types of lead-acid spill-proof batteries, wet/flooded lead-acid batteries are still very popular.
Since wet/flooded lead-acid batteries are NOT maintenance-free and they are NOT spill-proof, many people, unfortunately, come in contact with the smaller amounts of diluted sulfuric acid (H2SO4), which can be quite dangerous and can cause skin burns, damage the clothes, objects, car parts and similar.
So, how to neutralize and clean up small spills of lead-acid battery acid?
If You don't have time to make a baking soda/water solution, but You (skin, clothes) came into contact with a small amount of sulfuric acid, wash the skin and clothes with a generous amount of plain water - water will not neutralize the acid, but diluted it to the point where it cannot cause acid burns or burn through the clothes.
Also, the washed-away amount of sulfuric acid is very small, and its environmental impact is negligible.
If the amount of battery acid is substantial (not just a few drops), mix one cup (240 ml, ~200g) of baking soda with a gallon (~3.8 liters) of water and wash your hands, clothes, and affected surfaces with this mixture.
Baking soda is a weak alkali and is safe for skin and most car parts and clothing.
After neutralizing the acid (no more fizzling, for example), wash everything with plain water to remove any baking soda residue.
If your skin was exposed to the battery acid, and especially if your eyes or mouth were exposed to the battery acid, after neutralizing the acid and washing soda, contact your doctor immediately.
Can Baking Soda Safely Neutralize Large Forklift And Similar Lead-Acid Battery Spills?
Short answer, with no math or chemistry: No, baking soda is not suitable for neutralizing spills of battery acid from large batteries.
And here comes a little bit longer answer...
Baking soda is sodium bicarbonate with a chemical formula of NaHCO3 and a molar mass of 84.0066 g/mol (~84 g/mol), while the battery acid is diluted sulfuric acid with a chemical formula of H2SO4 and a molar mass of 98.079 g/mol (~98 g/mol).
The equation of neutralization of sulfuric acid with baking soda is:
2NaHCO3 + H2SO4 → Na2SO4 + 2H2O + 2CO2
This means that one needs 2 moles of sodium bicarbonate to neutralize 1 mole of sulfuric acid and to create 1 mole of sodium sulfate (more or less neutral), 2 moles (36g) of water, and 2 moles (88g) of carbon dioxide.
Or in grams, one needs 168g of baking soda to neutralize 98g of sulfuric acid.
Forklift come in various dimensions, and so does their battery packs. But, very often, a battery pack consisting of four 8D lead-acid batteries is used to power such and similar vehicles and is used in industry to power various electric tools and devices.
A typical 8D lead-acid battery weighs ~150 pounds (~68 kg) and contains ~25-30 pounds (~11.3-13.6 kg) of electrolyte, which is diluted sulfuric acid.
Note: these values vary and are dependent on a battery model, remaining battery charge, and similar - this is just an example to show why baking soda is NOT suitable for neutralizing and cleaning up of large lead-acid battery acid spills.
The amount of sulfuric acid in an electrolyte varies from 30 to 50%, but it is safe to say that a fully charged, 150 pounds lead-acid battery contains between 3.4 kg and 6.8 kg of sulfuric acid.
If the battery pack consists of four such batteries and all four batteries are leaking (the forklift had an accident, for example), that means that the spill contains between 13.6 and 27.2 kg of acid.
Such an amount of acid requires at least 23.3 to 46.6 kilograms of baking soda for complete neutralization.
First of all, this is a small battery pack for an electric forklift, with some models having 3-4x heavier battery packs.
Second, such an amount of baking soda is hard to work with, requiring plenty of water to make a safe mixture for cleaning (again, one cup of baking soda mixed with a gallon of water).
Third, if baking soda is directly mixed with battery acid (who has time to mix it with water, right?), chemical reactions between baking soda in powder form and diluted sulfuric acid can be rather energetic, with plenty of CO2 being produced, not to mention acid vapors, droplets, etc.
In short, complete and very dangerous mess.
That is why warehouses and industrial plants using or manufacturing lead battery acid must have trained personnel, protective gear, and professional acid absorbents to be used if something goes wrong...
How To Neutralize Alkaline Battery Electrolyte
Alkaline batteries are much smaller than car and similar lead-acid batteries, but they nonetheless contain electrolytes that can leak out and cause chemical burns and damage the equipment.
Fortunately, they are much easier to neutralize.
If your hands come into contact with the electrolyte of an alkaline battery, put some vinegar on the affected skin and then wash your hands with plenty of water and some mild hand soap.
If there is some battery electrolyte left in the battery compartment of the device, use a toothbrush with some vinegar or lemon juice and scrub the affected parts of the battery compartment.
After the fizzling stops, clean the vinegar or lemon juice with some water, and that is all.
Since alkaline batteries are used even in standby devices that don't operate for years but must operate at the moment of notice (EDC flashlights, for example), it is highly recommended to power such devices using high-quality alkaline batteries from reputable brands that are guaranteed leek-proof.
How To Clean Up Lithium Battery Electrolyte
Lithium batteries are generally leak-proof, but from time to time, they may get damaged, and their electrolyte may leak out.
If that happens, the battery is considered dangerous since it can overheat, catch fire or even explode - damaged lithium batteries should be placed in fireproof bags and recycled properly.
Their electrolytes are washed away using plenty of plain water, diluting any aggressive liquid that may cause damage or injuries.
Long Story Short: If the battery leaks, regardless of the actual chemistry, consider the leaking electrolyte dangerous to touch and breathe.
When working with the battery electrolytes, always wear protective gear (gloves, goggles, mask, etc.) and try to stay safe.
If a big lead battery acid spill happens and You don't know what to do, leave the area immediately (go out, get some fresh air) and let the certified professionals deal with the spill.