We have a series of videos and blog posts to help you properly handle lye.
Here are the basics. The direct links are listed 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.
Here's our lye safety video.
Blog post about troubleshooting lye heavy soap.
Soap Queen video about lye safety.
To purchase sodium hydroxide for bar soap click here.
To purchase potassium hydroxide for liquid soap click here.