Like many, my wife and I fell for the Koh Cleaner advertisements on Facebook. While their surface cleaner works, you’ve probably heard (or maybe not) that Koh is mostly water. In fact, the active ingredient, potassium hydroxide (KOH), comprises about 0.5% of the total solution, with the rest being purified (distilled) water.
Below is a safe and accurate way to make a roughly 0.5% KOH solution at home for a fraction of the cost, what’s often referred to as a homemade Koh cleaner.
Ingredients:
- 1 litre (1000 ml) of distilled water
- 5 grams of potassium hydroxide (KOH)
Instructions
- Preparation:
- Work in a clean, dry area.
- Wear appropriate personal protective equipment (PPE): gloves, eye protection, and long sleeves if possible.
- Remember, KOH is a caustic substance. Avoid contact with skin, eyes, and mouth, and ensure there is good ventilation.
- Measure the Water:
- Measure out 1 litre (1000 ml) of distilled water.
- Pour it into a suitable container—glass or HDPE (high-density polyethylene) are the most resistant to strong solutions.
- Weigh KOH:
- Using a precise scale, measure 5 grams of KOH.
- Double-check your measurement; accuracy is important for both safety and effectiveness.
- Add KOH to Water (Never the Reverse):
- Slowly add the KOH to the water while stirring gently.
- This prevents a sudden, intense heat spike that can occur if water is poured directly onto KOH.
- Dissolve KOH:
- Double-check your measurement; accuracy is important for both safety and effectiveness.
- Slowly add the KOH to the water while stirring gently.
- This prevents a sudden, intense heat spike that can occur if water is poured directly onto KOH.
- Dissolve KOH:
- Continue to stir until all KOH flakes or pellets are fully dissolved.
- The solution will likely warm up (exothermic reaction). Allow it to cool to room temperature.
- Storage:
- Once the solution has cooled, transfer it to a clearly labeled container with the name of the solution and the date made.
- Keep it out of reach of children and pets.
- Clean Up:
- If any solution spills, rinse the area well with water.
- For small spills, you can neutralise with vinegar or a diluted citric acid solution.
That’s it, your own homemade Koh Cleaner with about a 0.5% KOH concentration. Because it’s a strong alkaline solution, use it carefully and test it on an inconspicuous area before applying to larger surfaces. With the proper safety steps, making this solution should be straightforward, cost-effective, and just as usable as the bought version for a fraction of the cost.