Starting today, we are revisiting the basics of cold process soap with the Back to Basic series. Over the next two weeks, we will cover basic concepts and tutorials designed for the beginner in mind. If you have never made cold process soap before, now is the perfect time! The Back to Basics Soapmaking Kit includes all the ingredients you need to make all 4 projects. If you are a seasoned soaper, it’s always good for a little refresher course. For our first lesson, we are covering the most important part of soaping (other than having fun)…safety! In particular, we are chatting about lye safety, including how to safely mix and handle your lye solution. Pencils ready? Let’s get started!
In order to make soap, oils must emulsify with lye, which begins the saponification process. During this process it’s important to make safety a top priority. Sodium hydroxide lye is an inorganic compound commonly found in drain cleaners like Draino. Sodium hydroxide lye is highly caustic and has the potential to burn the skin. Like driving a car, sodium hydroxide is safe when handled properly. But because lye has the potential to be extremely dangerous, it’s important to take every safety precaution when making cold process soap.
Sodium hydroxide lye is available in various forms, such as flakes, pellets and powder. To make cold process soap, lye is introduced to a liquid like distilled water. The liquid dissolves the lye and creates a lye solution. Mixing water and lye creates an exothermic reaction that causes a dramatic temperature increase. Adding lye to room temperature water can cause the water to reach temperatures up to 200 ° F. The mixture also creates fumes, which should not be inhaled.
Yes, all this information sounds a little scary, and it’s totally normal to be nervous when first working with lye. Luckily, it’s easy to protect oneself from harm when creating lye solution. Below are my basic lye safety tips. I also recommend watching the How to Make Cold Process Soap: Lye Safety & Ingredients video below.
Wear Proper Safety Gear: When working with lye, wearing protective safety gear is a must. This includes eye goggles, gloves, long sleeves and long pants. Covering your skin helps protect it from spills or drops of lye solution. Some soapers also like to wear surgical masks to avoid breathing in any fumes.
Mix Lye in an Appropriate Place: The area in which you mix your lye solution should have good ventilation to avoid breathing in lye fumes. When weather allows, some soapers like to mix their lye solution outside to get the best ventilation possible. When indoors, I like to open a few windows or turn on a fan. In addition to ventilation, it’s important to make sure kids, pets and other distractions and tripping hazards are out of the house or don’t have access to your soaping space. Some soapers prefer to soap with a ventilator or air filter on to help filter out any fumes that happen during the mixing process.
Always Add Lye to Water (Never Water to Lye!): When mixing water and lye the first step is to measure the correct amounts into separate containers. Once you have the correct amounts for your recipe, the lye should be slowly added to the water. NEVER add water to your lye! Doing so can cause the lye to expand, or erupt, out of the container. A popular rhyme to help you remember the order is: “It’s smarter to add lye to water! Add water to lye and you may die!” It’s definitely an extreme rhyme, but it can be helpful in the beginning!
Use an Appropriate Mixing Container: It’s important to mix your lye solution in a durable and safe container. The container should be a sturdy, heat-resistant plastic or glass. I don’t recommend mixing lye solution in a metal container. This is because the lye solution gets incredibly hot. It’s also because lye and some metals produce a hazardous reaction. Sodium hydroxide and aluminum produce hydrogen gases, which can be extremely dangerous. Lye also reacts with tin. To be on the safe side, I avoid metal containers entirely. If using glass, make sure your container is extremely sturdy. I have used Pyrex containers successfully for years, but I know some soapers have had experience with these containers breaking. On occasion, I also use Easy Pour and Mixing Containers to mix my lye, as they are made out of a sturdy plastic. I recommend choosing a container that is large enough to catch any splashes as you stir. To be extra safe, mix your lye and water over a sink in case there are any spills.
Store Lye Appropriately: While waiting for the lye solution to cool to suitable soaping temperatures, make sure your container is clearly labeled “LYE” to ensure nobody touches or tampers with the solution. It’s also helpful to move it to a place where kids or pets will not touch or drink the solution. The jar of lye flakes, pellets or powder should always be kept out of reach of children, and should be properly labeled “POISON,” or “DO NOT TOUCH,” to ensure people do not tamper with the lye.
If You Get Lye on Your Skin: According the sodium hydroxide MSDS (Material Safety Data Sheet), if your skin comes in contact with lye, remove any contaminated clothing. Flush immediately with plenty of water for at least 15 minutes. Seek medical attention. If it comes in contact with eyes, flush immediately with water for at least 15 minutes and get medical attention. If inhaled, move to fresh air.
Many soapers keep vinegar on hand, believing it neutralizes lye burns. There is some controversy in the soapmaking community about washing lye burns with vinegar rather than water. Adding vinegar (an acid) to lye (a base) creates a chemical reaction that releases more heat. Additionally, the act of putting vinegar on a lye burn hurts. Just use water as the MSDS sheet suggests.
Although vinegar should not be used to treat lye burns on skin, it can be used as precaution during the cleanup process. A quick wipe of your workspace with a vinegar-soaked rag will neutralize any lye dust that may have gotten on the surface.
Now that you have safely mixed your lye solution, it’s time to make cold process soap. But safety doesn’t stop here! During the entire soap making process, it’s important to wear your safety gear which includes goggles, long sleeves and pants, and gloves. This is because the lye solution still has the potential to irritate the skin once mixed with soaping oils.
Once you pour the lye solution into the oils and begin to emulsify, the saponification process begins. For an in-depth explanation of what saponification means, check out this blog post and Soap Queen TV video. As the saponification process develops, the lye solution becomes less caustic. Raw soap batter is not as dangerous as pure lye water, but it can still irritate the skin. Wearing saftey gear while soaping helps avoid any contact with the soap batter. If soap batter touches the skin, you may not notice until several minutes later when your skin begins to tingle and burn. Quickly wash away any soap batter on the skin with water and a gentle soap. Once saponification is complete, all lye molecules have been transformed into soap and will not harm the skin.
The soap above has reached a thin trace. If you were to get the mixture on your skin, wash it off immediately under cool water for several minutes until the itching or burning subsides.
After you’re done soaping, it’s time to wash your dishes. Because the soap will still irritate the skin, leave your gloves on while washing any soaping dishes. I recommend wiping out any excess soap with a paper towel, then washing your dishes in the sink with hot water and grease-cutting soap like Dawn. If you want to avoid washing oils down the sink, you may prefer the “garbage bag clean up method.” Read about each clean up method in the Soapy Session Clean Up Guide.
Making cold process soap is extremely rewarding and fun. During my entire “soaping lifetime,” I have never experienced a serious lye burn. I have experienced both lye water and soap batter on my skin, but was able to wash it off right away with no serious harm done. The worst injury I ever experienced while soaping was when I got fresh soap in a cut on my hand…ouch! I attribute my soaping good fortune to always taking the extra steps to ensure safety for myself and people around me. Much like wearing a seat belt when driving a car, proper safety precautions are the first step in creating homemade soap. What steps do you take to ensure you are soaping safely? I would love to hear your input!
Be sure to check back tomorrow for our first cold process recipe, a Simple & Gentle Cold Process recipe. It’s the perfect soap for somebody who has never tried cold process soaping before.
