Soap Making Safety Guidelines and How to Safely Handle Lye

How to stay safe while making soap, with tips on how to safely handle lye, and a soap making safety checklist. This comprehensive guide covers everything from how to safely handle lye to setting up your workspace, cleaning spills, and personal protective equipment.

Here at Lovely Greens, I share a lot of small-batch soap recipes. They’re mainly cold process, but I share the occasional hot process soap recipe, too. What these tutorials have in common is that they always use lye.

In both hot and cold process soap, that lye is called sodium hydroxide, and it creates solid soap bars. In liquid soap making, the lye is called potassium hydroxide, and it creates a soap paste that you dilute with water.

Lye, in whatever form, is a caustic substance that is 100% necessary to make soap. However, it can be harmful if it’s not handled with care. You are not going to do that, though. Instead, you’re going to learn about lye safety, wear the necessary personal protective gear, and make soap safely. You cannot make soap without lye, but if you follow these safety precautions, then you and your family will be safe, and you’ll be on your way to making beautiful, natural soap.

Staying Safe While Making Soap

Many common skills have their dangers, but once you understand them, you start to feel comfortable and can use that skill without worry. For example, driving a car. Many things can happen when driving, and as a learner driver, you can be quite nervous. However, with experience and learning good habits, you’re able to get from A to B with no problems. The same goes for learning to safely make handmade soap.

The main safety concerns in soap making are handling and using lye. Some people avoid learning to make natural soap because of these fears. I hope that you’ll understand that soap making is not scary, though. If you show the process and ingredients respect and take measures to protect yourself and others, then you’ll be able to make batch after batch of beautiful soap with no issues whatsoever. Let me take you through what you need to know.

Soap Making Safety Checklist

There are many things we need to do to stay safe while making soap. Most are around the theme of protecting ourselves, our home, and our loved ones from contact with lye or lye solution. You also need to keep yourself protected from essential oils and other ingredients. I’ve created this soap making safety checklist to help you stay safe and successful each time you make a batch:

1. Wear eye protection.
2. Protect hands with lye-resistant gloves.
3. Use gloves that are also essential oil resistant: rubber, nitrile, or latex.
4. Wear clothes that cover your skin.
5. Wear an apron.
6. Protect your feet with closed-toe flat shoes.
7. Consider wearing a respirator mask while mixing the lye solution.
8. Work in a place where you won’t be disturbed.
9. Keep children and pets out of the room while soap making.
10. Ensure your workspace is clean and clear of clutter.
11. Use lye and heat-resistant equipment.
12. Make soap on a surface that won’t react with lye.
13. Keep paper towels and kitchen spray on hand.
14. For larger spills, keep a bag of non-clumping kitty litter on hand.
15. When making soap, work near a sink so that water is always available.
16. Mix the lye solution in a well-ventilated place.
17. Store lye and master-batch lye in a secure place.
18. Be familiar with the health information on the lye MSDS
19. Protect skin and eyes from essential oils.
20. Only use glass, metal, ceramic, or PPE containers/utensils with essential oil.

Importance of Lye in Soap Making

Lye is a natural substance made from brine in the chloralkali process. In the case of sodium hydroxide, the brine is made from water and table salt. Potassium hydroxide uses the same process but is made from a brine made from water and Potassium chloride. You may have also heard that lye can be made by leaching rainwater through wood ashes. That’s true, and the caustic liquid that results contains Potassium hydroxide. However, there’s no way for the average person to accurately measure how much of it is in homemade lye. That’s why we no longer use it if we want to make soap safely.

A common question with beginner soapmakers is if you can make soap without lye. Often, the aim is to make soap with as many natural ingredients as possible, and it seems contrary to using a “chemical” like lye. The fact of the matter is that lye is a hundred percent necessary to make soap. There’s a pre-made soap base called melt-and-pour soap, but it’s either synthetic (detergent-based) or the lye part has already been done in advance for you. If you want to make natural soap, you need to use lye.

Saponification Takes 48 Hours

In soap making, incredible things happen when we mix lye and fats/oil together. As they interact, their original molecules break apart and then reassemble with one another. This process is called saponification, and the result is natural soap—a unique and natural chemical compound. That means that most of the oils/fats and all of the lye in soap recipes don’t exist in their original form in soap bars.

Still unsure? I like to use the baby analogy to help illustrate what happens in soap making. Most people know that a baby starts off as an egg from the mother and a sperm from the father. When these two “ingredients” come together, they fuse and become a baby. It’s easy to understand that there’s none of this original egg or sperm left in the baby. Along those same lines, know that there’s no oil/fats or lye left in soap molecules. They become the soap.

However, from a soap making safety perspective, it can take up to forty-eight hours for oils/fats and lye to become soap. During that time, the soap batter and the poured soap itself can still be caustic, and you shouldn’t touch them with your bare hands. Any soap residue left on countertops, tools, equipment, molds, and other surfaces could also be caustic. After two days, any residue will transform into soap and be harmless.

Personal Protective Equipment (PPE)

When making soap, you should dress yourself for the occasion. Wear clothes that cover as much skin as possible, then put an apron on over them. Long pants and long sleeves are ideal. Pull long hair back into a bun or braid and wear flat, sensible, closed-toe shoes. I also recommend wearing clothes that you don’t mind getting oil splatters on.

Clothing is your first defense against lye exposure, but the remaining parts of your body—your hands, face, eyes, and airways—need protecting, too. Rubber gloves are best for protecting your hands and lower arms, but you can also wear latex or nitrile gloves. I don’t recommend vinyl gloves since they can be damaged by essential oil, leaving you open to exposure.

Safety goggles are a must when making soap. Do not mess around with this one. Ordinary glasses will not cut it because they don’t wrap around your eyes and protect them from all angles. Safety goggles are designed to be worn over glasses, but if you don’t wear glasses, you can wear onion goggles to make soap if you wish. They’re cuter, and the foam liner stops any lines from imprinting on your skin.

Lastly, and somewhat optionally, you can wear a respirator mask while mixing the lye solution. The steam that’s let off during this step can burn or damage your airways if breathed in. The risk of this is much lower when mixing lye solution for small batches of soap. In that case, working by an open window and avoiding breathing in the lye fumes is fine. However, if you’re making larger batches, you should seriously consider buying and wearing a respirator mask.

Your Soap Making Area

Professional soap making studios are dedicated spaces exclusively for making soap. Usually, they’re rented spaces furnished with stainless steel work surfaces and sinks, shelving, and cupboards for storing ingredients and equipment, curing racks, and hard floors. Everything is kept clean, tidy, and free of clutter, which helps you make soap safely and efficiently. It’s well-lit and well-ventilated, hazards are evaluated and minimized, and there are first aid kits and cleaning materials at hand.

Hobby and small-business soapmakers often set up a smaller-scale version of this in a room in their homes. This can be a soap-making area in a spare room, garage, basement, or outbuilding. However small the space, having a dedicated area for soap making will help keep you and your family safe.

When you’re first starting off making handmade soap, it will often be in your kitchen. This is perfectly fine, but you do need to ensure that it is set up to be just as clean, tidy, and safe as any soap studio. I highly recommend completely clearing the counter and sink where you’re working. Do not have food on the counters where you’re making soap. Move pots of utensils away from where you’re stick blending. And always work so that you’ll be undisturbed – that means keeping children and pets away when making soap.

Preparing Your Work Space

The first step in preparing to make soap is setting up your workspace. When it’s clean and clear and you’re properly dressed, it’s time to get organized. All the equipment you’ll be using should be clean and set out, ready to go. Doors should be shut, and windows near your soap making area open.

If you have cats or other animals that come in through windows, make sure the windows are not open enough to let them in. You should also have a roll of paper towels and kitchen spray on hand for spills and cleaning up.

Being prepared is the key to soap making safety. Part of that is ensuring that all of the ingredients you’re using are pre-measured. If you try to measure ingredients as you make soap, it can lead to mistakes. Some of the mistakes that come to mind include missing an ingredient, forgetting about oils heating on the stove, and soap batter getting too thick to add soap additives to.

Keeping Records

While making soap, you should also have the recipe you’re using on hand. You should also have a notebook to take notes on the particular batch you’re about to make. Notes should include the date, the recipe, the temperatures you use, any techniques (such as oven processing) you use, and anything else that happens while making the batch. This will help you identify any issues that arise later down the line. It also helps you figure out successes so that you can replicate them for future batches. Professional soap makers also record the batch number and the batch numbers of the specific ingredients used.

Kitchen Utensils for Soap Making

One somewhat contentious topic in soap making is whether or not you can use kitchen utensils and equipment to make soap. In an aspirational situation, all of your soap making equipment should be dedicated to soap making. However, as a beginner, you’re trying to learn a new skill from home without breaking the bank. Here are my thoughts on the topic.

Lye and lye solution is a caustic and potentially dangerous material, and it should be kept far away from contact with people, animals, and food. However, lye does not soak into materials and does not contaminate them if cleaned thoroughly. Running stainless steel pots, pans, spoons, bowls, and ramekins through the dishwasher removes lye from them completely. I think that it’s perfectly acceptable to use these items for soapmaking and cooking if care is taken to completely clean them. Don’t use aluminum, cast iron, or copper items for soapmaking. Lye can react with these metals.

Equipment to Reserve for Soap Making Alone

Stick blender heads that are stainless steel and can be removed for cleaning are also okay to use for both, in my opinion. If you’re using a plastic model or the head cannot be removed, I’d reserve it for soapmaking only. Not just because it’s difficult to remove any residue from inside the head but also because plastic is damaged by and absorbs essential oil and fragrance oil. Both of these are not to be consumed, and the scent can also contaminate food.

The same goes for silicone molds, spatulas, and anything else that’s plastic and comes in contact with fragrance. They will not only pick up the scent over time but can also be contaminated with it. Lye is often not the real issue with reusing kitchen utensils in soap making—it’s the essential oils.

Essential Oil Safety

Although essential oil is a natural ingredient, it must also be handled with care. Skin contact or ingestion can result in burns, rashes, or poisoning. Reactions differ based on the essential oil, the allergens it contains, and the concentration of the exposure. Lavender oil is probably the most gentle essential oil, but the typical hazards listed on its MSDS include skin irritation, serious eye irritation, and death should it be swallowed and get in your airways.

Do not underestimate how dangerous essential oils can be, and always wear non-vinyl gloves when handling them neat. Essential oils can dissolve many plastics, which is why they must be stored in glass, metal, or polypropylene containers. The same goes for fragrance oils, which are synthetic scents that may also contain essential oils. Though they add beautiful plant-based fragrances to handmade soap, you should not exceed the recommended essential oil usage rates in soap recipes, either. Use too much and your soap could cause an allergic reaction.

Safely Making Lye Solution

One of the first things you do when making soap is mixing the lye solution. Lye, both sodium hydroxide and potassium hydroxide, comes in a solid, granular form. It cannot mix with oils in this form, so we need to dissolve it in cold to tepid water, creating a lye solution. To safely mix them, always wear PPE and work in a well-ventilated space. The water should always be in a heat and lye-resistant container such as a polypropylene jug. I also recommend mixing the lye solution in a sink or a basin just in case of spills.

To make a lye solution, pour the granular lye into the water in one go and mix it immediately with a stainless steel or silicone utensil. Mix until the lye is completely dissolved, then leave it to cool.

When we mix lye and water together, not only does the lye dissolve, but an exothermic reaction takes place. This reaction releases heat, and the tepid water you use suddenly heats up to 200 F (93C). Fumes also come off the lye solution, and you should not breathe them in. The fumes disappear once the lye solution cools, but until then, keep it near a cracked window or wear a respirator mask.

It’s also important to use cool to tepid water when making a lye solution. Warm water, as in the case of herbal tea, can cause the lye solution to volcano out of the jug. Mixing the lye solution by pouring water into the granular lye can also cause this—we only pour the lye into the water, not the other way around.

Cleaning Up After Soap Making

After making the lye solution, you treat it and the raw soap with as much care as possible. You wear gloves and goggles while making it and pouring the mixture into soap molds. What do you do at the end of the process, though? You’ll have pans and utensils covered in caustic residue, and there may even be some on the counter or other surfaces. Keep your PPE on because you’ll need it to protect yourself while tidying up.

I go through safely cleaning up after soap making in detail in another piece. What you’ll need to do is wipe up any spills or overly messy equipment. Counters, floors, and other surfaces should be cleaned with warm, soapy water and the dishes washed. It’s best to do it by hand, but if they are wiped down, you could also run them through the dishwasher. If there’s too much soapy residue on them, it can turn into a foamy mess that will come rushing from the dishwasher, though. I’m speaking from experience!

Some soapmakers set their soapy pans and equipment aside for two days before they wash them. This is mainly about avoiding oily soap residue going down your pipes. Lye becomes inert with exposure to water and air, but the oil and congealed fat can clog up pipes and septic tanks over time. If you wait two days before cleaning equipment, the oils/fat and lye will have gone through the full saponification process and will be soap. That means you’ll mainly have soap going down the drain after that.

Lye Spills on Surfaces

Unsaponified soap batter on surfaces is best cleaned up with paper towels and thrown away. Lye spills are different, though. If you spill granular lye, sweep it up, pour it into cold water, and mix it like a lye solution before pouring it down the sink. Do not try to vacuum it up. Lye grains will absorb moisture from the air inside your vacuum and can cause a hazard.

If a little lye solution spills on the counter, wipe it up with paper towels and dispose of it in the trash. As the paper towels dry, the remaining lye on the paper will react with the air and become inert, becoming soda ash.

Larger spills are more serious. If you spill more than can be absorbed by paper towels, pour non-clumping kitty litter over it. The clay in the kitty litter absorbs the lye solution, and you can then scoop it up and put it in a lye-resistant container or bag before throwing it away. You can keep a bag of kitty litter in your soap room storage just in case of a scenario like this.

Using Vinegar to Neutralize Lye

Anyone who has seen Fight Club will remember the scene where Brad Pitt puts lye on Edward Norton’s hand. He then pours vinegar over it to end the pain and neutralize the lye. This scene is pure Hollywood, but there is some truth in the idea that vinegar (acetic acid) can neutralize lye. With caveats.

The first is that you need about a gallon of vinegar (5% acetic acid) to neutralize about 127 grams (4.5 ounces) of lye. What a mess that would make! Also, when vinegar and lye come into contact, they react by creating intense heat. It would severely burn you or other surfaces before the lye is neutralized. That’s why using vinegar is not a great solution for lye spills. Using diluted vinegar spray on surfaces and soap equipment after clean-up is harmless but probably also ineffective.

Storing Lye

When I order lye, it comes in sealed polypropylene (PP) plastic containers, and I keep it inside until I need to use it. I store these bottles of lye on shelves inside a cupboard, where it’s dry and kept safe. I feel that this is the best way to store granular lye until you can use it. Large bulk orders may arrive in sealed plastic bags, though. Once you open them, you either need to store the lye in another sealed container or make master-batch lye with it and then store it in a sealed lye-resistant container.

Storage is so important for soap making safety because granular lye attracts moisture from the air. If the lye gets just slightly damp, the grains will stick to one another and become a rock-solid lump. You’ll have to throw it out. If the room has high humidity, the lye can even absorb enough moisture to become liquidy, causing a dangerous mess. However, if lye is kept sealed and dry, it has an indefinite shelf-life.

Dangers of Lye in Soap Making

Solid lye granules, lye solution, soap batter, and the fumes that come off lye solution are all dangerous. But how dangerous are they? It all depends on how concentrated the lye exposure is, where the exposure happens, and how quickly you act afterward. It’s imperative that you read the full material safety data sheet (MSDS) for sodium hydroxide to understand the most extreme consequences. I’ve pasted the main ones below, and as you can see, there are a lot of other not-fun things that could happen. Please do not freak out, though. Have faith in yourself that you’re not going to do something silly and are instead going to stay safe while making soap.

• Eye: Causes eye burns. May cause blindness. May cause chemical conjunctivitis and corneal damage.
• Skin: Causes skin burns. May cause deep, penetrating ulcers of the skin.
• Ingestion: May cause severe and permanent damage to the digestive tract. Causes gastrointestinal tract burns. May cause perforation of the digestive tract. Causes severe pain, nausea, vomiting, diarrhea, and shock.
• Inhalation: Irritation may lead to chemical pneumonitis and pulmonary edema. Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. Causes chemical burns to the respiratory tract.
• Chronic: Prolonged or repeated skin contact may cause dermatitis. Effects may be delayed.

Material Safety Data Sheet Sodium hydroxide, solid

What to Do After Lye Exposure

The most likely scenario that could happen is that droplets of lye solution or caustic soap batter get on your skin. It’s happened to me a couple of times, and you’ll know when it happens because it burns. Should this happen to you, walk calmly to the sink and rinse the area with cold water. The MSDS advice is to rinse the area for fifteen minutes. Often, your skin will not have a visible burn and will feel okay after rinsing, but if the exposure is severe, you may want to contact medical services or poison control.

You should also remove any clothing, shoes, gloves, or other items that have caustic material on them and not wear them again until they’re washed. Clothing can be washed in the washing machine, and other items should be washed with water and dish soap.

In my experience, I once got lye on my arm, and the other time, a fleck of lye solution got on my cheek. I was anxious but stayed calm and rinsed my skin thoroughly on both occasions. Thank goodness I was wearing safety glasses since they kept my eyes well-protected.

Lye Contact with Eyes, Mouth, and Lungs

Skin contact with lye is painful and burns, but contact with your eyes or esophagus is more serious. If you should get lye in your eyes, immediately flush them with cold water. Flush them for fifteen minutes before getting someone to take you to the hospital.

If you breathe in fumes, you will immediately start coughing. If this happens, move away from the lye solution and get some fresh air. For more serious inhalations, get medical help.

Accidentally drinking lye or getting it in your mouth is very serious. Again, get medical aid, but do not try to make yourself throw up. Drink a cup of water and/or rinse your mouth with water.

Soap Making Safety

The last couple of sections have been quite scary, so if you’re feeling a bit nervous, take a deep breath. Lye accidents are rare, especially if you understand the risks and take precautions. People make soap safely every day and it’s an exciting skill and artisan craft that will have you hooked in no time. Don’t let fear hold you back—it will do you no favors.

The important thing is to avoid accidents by handling lye safely, protecting yourself and others from exposure, and cleaning up your workspace properly. Hopefully, I’ve covered everything, but if you have any questions, please leave me a comment. Have a great time soap making, and if you’re new to it, here’s more information that will help you on your journey:

1. Introduction to Soap Making
2. Natural Soap Ingredients
3. Soap Making Equipment
4. Soap Making Safety
5. Easy Soap Recipes
6. How to Make Cold Process Soap