Safety precautions for soap making: a complete guide
Cold process soap making is a process that anyone can carry out in their own kitchen. However, it involves handling lye (or caustic soda or Sodium Hydroxide), a chemical that can cause severe chemical burns if it comes into contact with your skin or eyes. Therefore, it is extremely important to take all necessary safety precautions! In this article, we’ll provide all the instructions you need to make soap at home safely.
Contents at a glance
Below is a quick overview of the topics covered in this guide. Click on any of the links to jump directly to the corresponding section:
Wear protective gloves, goggles or a full face shield
Lye is highly caustic and can cause severe chemical burns if it comes into contact with your skin or eyes. Therefore, always wear rubber gloves when handling lye.
Some people prefer using disposable latex or nitrile gloves, but these have two drawbacks: a) they are short, leaving your wrists exposed, and b) they are thin and can tear easily. Personally, I strongly recommend using heavy-duty cleaning gloves, which are longer and more durable, minimizing skin exposure.
Lye is extremely dangerous to the eyes. Always wear protective goggles when making soap. Regular eyeglasses are not sufficient - you need to wear goggles over them (just make sure the goggles can accommodate your eyeglasses!).
For large batches, I strongly recommend using a full-face protective shield, as it protects your entire face from accidental splashes while stirring the soap. I always use one when making large batches.
Do NOT use aluminum or galvanized pots, containers or utensils
Since lye is highly caustic, it will corrode and destroy aluminum or galvanized containers, spoons, and other utensils. Additionally, the reaction between lye and aluminum can produce toxic fumes.
Always ensure that you only use containers and utensils made of stainless steel or specific types of rubber or plastic (read more below).
Do NOT use glass containers for the lye/water mixture
When lye and water mix, a large amount of heat is generated, causing the temperature of the solution to rise considerably (above 75°C/170°F).
Glass containers should NOT be used for dissolving lye in water, as they may crack or shatter due to the heat. Instead, use a heat-resistant container, such as stainless steel or plastic. If using a plastic container, ensure it can withstand the high temperatures generated (e.g. a polypropylene jug is ok).
To be on the safe side, my recommendation is a stainless steel pot!
Use cold water to dissolve the lye
As mentioned earlier, the reaction of dissolving caustic soda in water generates a significant amount of heat.
During the warmer months of the year, if you prepare a caustic soda solution using water at room temperature, the temperature of the solution may rise so much that it could approach the boiling point!
It is therefore advisable to use cold water (from the fridge) to dissolve the lye (pearls, beads or flakes).
This helps prevent the solution from becoming excessively hot, which is not only safer but also helps the solution cool down more quickly to the desired temperature, making it ready to be added to the fats and oils.
Do not touch the lye mixture container with bare hands until it has cooled down.
As mentioned earlier, the mixture can become extremely hot (reaching temperatures above 75°C/170°F), and the intense heat can cause burns if the container is touched.
Always pour lye slowly into water (not the other way around! )
Always pour lye (pearls, beads or flakes) into water slowly and steadily while stirring.
Never pour water onto dry lye, as this can cause dangerous splashing or even an explosive reaction!
Lye fumes can be dangerous
When dissolving lye in water, fumes are produced. Ensure you perform this step in a well-ventilated area - or outside, if possible. Always avoid inhaling lye fumes.
Fumes from small soap batches are generally not strong enough to cause problems - in a fairly large kitchen, they are barely noticeable. However, larger batches produce significantly more fumes.
Prolonged exposure to these fumes can cause eye irritation and make the skin feel as if it has been sunburned.
For smaller batches, I prefer to place the container with the lye solution near an open window. For larger batches, I prefer to mix the lye and water outside.
If you choose to prepare the lye solution outside, ensure that no pets, children, elderly individuals, or wildlife can access it.
About using a mask or respirator for lye fumes
Some people use a mask or respirator when handling lye. While this is not mandatory, here are some factors to consider so you can decide for yourself:
- Simple masks (surgical masks, K95) are not sufficient. Although they are better than nothing, they are not designed to block chemical fumes.
- A respirator designed for chemical protection is the proper choice for blocking lye fumes (if you choose to use one at all).
- Wearing a mask or respirator, along with the eye-protective goggles (and possibly eyeglasses for some of us) can be quite cumbersome. Issues like fogging eyeglasses or difficulty breathing may become distracting during critical phases of the soap-making process.
- For small batches, as long as you avoid inhaling lye fumes when preparing the lye solution, a mask or respirator is not necessary.
- For large batches, consider using a respirator if a well-ventilated workspace (or working outside) is not an option.
Be careful when moving the container with the lye solution
When moving the container with the lye solution from one place to another, step carefully to avoid spilling any.
Use a container that can accommodate the lye solution while remaining half full.
Securely store lye and other dangerous chemicals
- Do not store caustic soda in cabinets near food or beverages, where it could accidentally be mistaken for a cooking ingredient!
- Store containers with dry lye tightly sealed and away from moisture. Otherwise, the dry lye will absorb moisture and form lumps, which are difficult to dissolve.
- If you have small children, keep lye securely locked away in a cupboard, out of their reach.
Clothing
- Avoid wearing jewelry or loose clothing, such as wide sleeves or long skirts, while making soap.
- If you have long hair, tie it back to prevent it from dipping into the lye mixture and potentially rubbing against your face.
- Wear clothing that covers and protects your body as much as possible. Do not wear flip-flops, as a drop of lye could accidentally fall on your foot and cause a burn. Opt for trousers instead of shorts - you get the idea!
- Consider using a long-sleeved lab coat. This will not only protect your skin but also your clothes from accidental lye or fresh soap splashes.
- Personally, I prefer disposable back-closing lab coats. They can be thrown away once they get too dirty from splashes (and believe me, this happens more often than you might think). Additionally, in case of a large lye splash, they can be removed quickly before the lye penetrates your clothing and skin.
More safety tips
- If using dry lye flakes, lye "dust" can become airborne when scooping from the bag/container or pouring into water. Avoid inhaling the dust from the lye flakes!
- Children, pets, and individuals with cognitive disabilities should not be present in the work area while you are making soap.
- Prepare and organize your workspace in advance, keeping it neat and tidy. A cluttered workspace can lead to distractions, which may compromise safety.
- Do not leave food or drinks (e.g. coffee) on the counter where you are making soap. This is an essential rule that applies to all chemical laboratories, by the way!
- After soap making, keep wearing your protective equipment while cleaning your utensils and containers. Remember that fresh soap is caustic as well (soap is not lye-free until approximately 2 days after making it).
- Always read the Material Safety Data Sheet (MSDS) provided by your chemical supplier for every ingredient you use - especially lye. This will help you understand the potential hazards of the materials you are handling and how to protect yourself.
- It’s a good idea to keep emergency medical phone numbers (e.g. Poison Control) readily available - just in case you need them in a rare situation.
If something goes wrong...
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If lye splashes on your skin:
- Immediately remove any clothing or jewelry that has come into contact with the lye. When removing contaminated clothing, take care to avoid spreading the lye to other parts of your clothes or skin.
- Rinse the affected area with plenty of cool running water for several minutes to remove the chemical and minimize tissue damage.
- Seek medical attention if the splash or burn is extensive. Call a medical emergency number or visit the nearest emergency room for professional care.
- Contrary to what some people suggest, do not use vinegar to neutralize lye. It can be ineffective, messy, and even dangerous. Instead, stick to rinsing the affected area with plenty of water, as described above.
- If you accidentally inhale lye fumes and feel the urge to cough, move away from the lye solution (or leave the room) and get some fresh air.
- If dry lye (pearls, beads or flakes) or dissolved lye (in liquid form) comes into contact with your skin, immediately rinse it off with plenty of running water. Note that lye on the skin at first feels slippery, followed by itching, and then a burning sensation.
- If fresh soap (while still in liquid form) comes into contact with your skin, rinse it off with plenty of running water.
- Lye can be fatal if swallowed. In case someone ingests lye, immediately seek medical help or take them to an emergency hospital. Do not try to induce vomiting.
- Lye is highly corrosive and can strip paint. If lye or fresh soap splatters onto a painted surface, wipe it off immediately, wash the area with water and detergent, rinse with clean water, and wipe it thoroughly.
Final considerations
I understand that the safety concerns described above might seem daunting to novice DIY soap makers.
However, don’t be intimidated. Staying safe while making soap is actually quite straightforward - thousands of people make soap at home safely every day.
So, get organized, wear personal protective equipment, and, above all, use common sense! The results can be truly rewarding!