Do you run a soap making business and you are concern about the handling of lye? If YES, here are 7 tips on how to safely dispose of lye water and crystals. While lye can be a helpful household product and even a drain cleaner, it is also quite dangerous. Lye, also known as caustic soda or sodium hydroxide, can cause burns, blindness or other serious injuries if mishandled. It can be fatal if swallowed.

If you use lye in your home, whether for making soap or clearing drains, you must be aware at all times of its highly caustic nature. It is important that you handle it carefully and dispose of any leftover lye properly and safely to avoid accidents.

What is a Lye?

Lye is a metal hydroxide that is traditionally obtained by leaching wood ashes, or a strong alkali which is highly soluble in water thus producing caustic basic solutions. Lye most commonly is known as sodium hydroxide (especially in manufacturing circles), but historically it has been used for potassium hydroxide (KOH).

Today, lye is commercially manufactured using a membrane cell chloralkali process. It is supplied in various forms such as flakes, pellets, microbeads, coarse powder or a solution. It is one of the main ingredients when it comes to soap making.

Uses of Lye in Soap Making

For soap to turn out properly, oils must emulsify with lye, which begins the saponification process. During this process it’s important to make safety a top priority as things can easily get out of hand. 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.

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.

With solution so caustic, many a soap maker have gotten into the dilemma of how to dispose their leftover lye after the soap making process. We are going to show you how you can easily dispose off your lye without posing health dangers to yourself and the environment.

7 Tips on How to Safely Dispose of Lye Water and Crystals

1. Make due consultations

Before you even start your soap making process, it would be a good idea to know what is acceptable in your locality when it comes to hazardous waste disposal. Consult your the hazardous waste collection agency locally for specific disposal instructions for your area. Lye is considered hazardous waste and is subject to federal, state and local disposal regulations. This would save you a lot of heartache later.

2. Not the drain

A lot of soap makers have often wondered if it is safe to dispose off left over lye in the drain. But you should know that this is not acceptable. Do not pour lye down the drain, into a toilet, storm sewer, on the ground, or put it in your trashcan to go out with your day-to-day trash.

3. Protect yourself while handling lye

It is imperative to protect yourself when handling lye, whether for use or disposal. Wear long sleeves, long pants, protective goggles and gloves when handling lye. You may also want to wear a dust mask, as inhaling lye dust or fumes is dangerous. Covering your skin helps protect you from spills or drops of lye solution. Some soapers also like to wear surgical masks to avoid breathing in any fumes.

4. 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, you can 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.

5. Do not pour water into lye

You must not be tempted to pour water into lye as doing so can cause a serious reaction. Water in lye causes a chemical reaction that generates heat that can reach combustible and even explosive temperatures. Do not attempt to wash lye down a sink with water.

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.

6. Be cautious

Use the utmost caution when handling lye. Do not allow it to spill or splash. Keep lye away from children and animals. This includes the disposal of lye: Do not dispose of lye in a place that is accessible to children, animals unsuspecting adults.

Transfer unwanted lye into a container made of stainless steel for disposal. Make sure the container has a tight-fitting lid. Do not store or dispose of lye in any container made of plastic, cast-iron, iron or aluminum, as lye corrodes these materials.

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. If using glass, make sure your container is extremely sturdy. You can use Pyrex containers but you have to take care so they don’t break on you. You should also use 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.

Note of Warning

Do not reuse the container in which you were storing the lye for anything other than storing 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.

Ejike Cynthia
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