Lye Handling & Safety Precautions for Soap Making
To make real soap, lye (either sodium or potassium hydroxide) is needed in order to emulsify the fats or oil i.e. saponification.
Sodium hydroxide and potassium hydroxide are alkalines that are highly caustic. Accidental exposure could cause skin damage, burns, blindness.
As such, it is very important that a soap maker take proper safety precautions when handling lye for soap making.
To make cold process soap (including hot process soap), lye is added to a liquid e.g. distilled water, to be dissolved, forming a lye solution.
Mixing lye and water creates an exothermic reaction that causes the solution’s temperature to increase dramatically (reach up to 100 degree celsius).
During this process, there could be fumes produced that should not be inhaled.
While these sound scary, with proper lye handling and safety precautions, a soap maker can still be well protected from harm.
Gloves: Always wear a pair of gloves to protect your hands from accidental contact with the lye or lye solution. Rubber dish gloves or nitrile/latex gloves would provide sufficient protection.
Googles or face shield: Accidental splashes of lye solution into your eyes could cause blindness. A soap maker should always protect your eyes with a safety goggle.
Long sleeves: Protects your arms from accidental splashes.
Long pants: Protects your leg from accidental splashes.
Closed-toed shoes: Protect your feet and toe from accident splashes.
Face Mask: This is optional but may help to prevent fume inhalation, especially if you are making a large batch of soap.
Add Lye to Water
The first safety rule for handling lye is to ALWAYS add lye to water, NOT water to lye.
Adding water to lye could cause pressure build-up resulting in lye solution exploding out of your container. Always add a small amount of lye into the water and stir gently to ensure the lye crystals are dissolved.
Separate soap making equipment
Equipment used for soap making should not be used for food. You should have a separate set of containers, spoons, spatula, etc that are not used for food consumption.
Don’t use aluminum containers or utensils
Aluminum will dissolve in strong bases such as lye. Adding lye to aluminum could cause a strong reaction and release hydrogen gas.
Use heat-safe container for lye solution
Make sure your container for lye solution is heat safe. Lye solution could reach potentially boiling point and always use a sturdy container that can withstand high heat. Some examples are stainless steel and polypropylene. Try not to use glass as it could shatter.
If you get lye on your skin
With the above safety precautions, you would have reduced the chance of direct exposure to lye. However, if your skin does come into contact with lye, remove the contaminated clothing immediately and flush with plenty of water for around 15 minutes or more.
If the lye solution came in contact with your eyes, flush your eyes immediately with water for at least 15 minutes and get medical attention. In the event of accidental fume inhalation, move away to an area with fresh air.
Making soap is fun and relaxing.
While lye can be dangerous, the risk of injury can be reduced with proper lye handling knowledge and safety precautions.
Just like driving, proper techniques and safety rules, are necessary.