#1 rule! ALWAYS pour NaOH/KOH into water. NEVER the other way around. Pouring water into NaOH/KOH will create an explosive reaction.
Lye will react with some metals. Do not use aluminum or tin. Ceramic, stoneware, heat-resistant plastic, or glass are best for mixing and storing lye. I use stainless steel, but must be careful of the handle as it can get quite hot. However, I prefer it over glass as I would certainly break it.
Test your plastic container before you mix lye. Place it upside down in your sink and pour very hot water over it. If it becomes soft or bendy, do not use it! If it holds up firmly, you’re good to go.
The reaction of mixing NaOH/KOH in water will generate heat. Be careful when touching the bowl/jar and use heat resistant items to stir.
Setting up your work area
Remove clutter! The less that you have to bump in to and knock around, the better. It’s important to protect the surfaces that you are working on. Drop clothes can be a great way to protect anything that you can’t remove from your counter/table, like cutting boards or appliances.
Find a pet/kid sitter while you are working with lye and raw soap. Pets can be secured in another room, if you can’t find help. Up to you if your kids can be shut in another room without issues.
VENTILATION! You are creating a chemical reaction. Don’t breathe the vapors coming off of the lye mixture as it reacts. If you can mix outside, even better. I mix mine under the hood of my stove at the highest power.
Personal Protective Gear
Now that you’ve protected your work space and put all pets and little ones away, you must protect yourself. Cover every bit of skin that you can. I often wear a man’s dress shirt, flipped around backwards. Then I can pop the collar up and protect my neck. Gloves are a must, and should be tucked in to or over long sleeves. Be sure to wear goggles!! Tie hair back. Long pants and socks/shoes are a good idea, in case of any splashing.
NaOH and KOH can come in tiny pellets or bigger flakes. No matter which sort you choose, it will get powdery at the bottom of the container it comes in. Wear a mask! I mistakenly breathed in powder from the bottom of a container and wow! Bloody, scabby grossness. If it did that to my nose and sinuses, imagine what it did to my lungs.
Choosing pellets vs flakes
The tiny pellets are a good option for pouring, as they mix easily. However, they can be impossible to control. In the winter, static can make them fly all over! Hence, making the drop cloth imperative.
The tiny pellets are sneaky! Since NaOH or KOH won’t react without moisture, I didn’t know that I had a tiny pellet on my lip. After my soaping project, I felt a bit of an itch, probably from the pellets reacting with perspiration. Then I licked my lip. That fully activated it! I was away from my sink by then, so it burned a decent little hole in my lip before I was able to rinse.
The flakes are easier to pour, but be careful in high humidity. NaOH/KOH will absorb moisture from the air, and the flakes are more likely to clump before and after pouring in to your water. This can mimic the “pouring water into lye” catastrophe. You will get a blow up!! Pour in to water slowly and carefully, stirring continuously to be sure that the flakes or pellets do not clump in the bottom.
You got some on you! What do you do?
If you get the dry NaOH/KOH on your clothing or skin, use a dry cloth or paper towel to brush into a sink or a garbage can. Once the dry flakes or pellets are removed, discard contaminated clothing or rinse skin under cool water to remove any residue.
For lye water and raw soap splashes, rinse skin continuously with cool water for several minutes. Many suggest a vinegar rinse, as it neutralizes lye. However, this neutralizing process is a reaction between the basic lye and the acetic acid in vinegar that causes heat (an exothermic reaction). This can burn! Therefore, where vinegar may work for tiny splatters and residue on surfaces, I do not recommend it for rinsing skin after contamination or for large spills on surfaces.
If you get it in your eyes, rinse with cool water for at least 5 minutes and get yourself to a doctor asap! Do not take this lightly!! You are risking permanent damage to your eyes. Also get to a doctor if it splashed into your nose or mouth.
If ingested, call poison control immediately at 1-800-222-1222. Do not make the person throw up unless told to do so by poison control.
Securing your area and your body takes the scary out of working with lye and raw soap. Start with small batches, as small spills are easier to contain that giant catastrophes.