Lye is a caustic, alkaline chemical that is useful for many purposes but also is hazardous. It can dissolve sticky substances such as fat and has a high degree of reactivity with other materials. Modern lye typically is the chemical sodium hydroxide, but potassium hydroxide was once the chemical compound that was commonly used. Whether in a flake, granular or liquid form, it is very dangerous and can cause damage to surfaces and people. Despite its hazardous nature, it is used in many common household products, such as laundry detergent and oven cleaner, and is even used to cure foods such as pretzels, green olives and mandarin oranges.
Sodium hydroxide is created using a chemical reaction between soda, or sodium carbonate, and calcium hydroxide, or lime. In raw form, it is made into solid flakes, chips or grains. Chemical suppliers provide sodium hydroxide to manufacturers for use in the making of a wide variety of products, such as fabric, paper, hand soap, metal polishers and drain de-cloggers.
Before the modern manufacture of lye, people were able to make it out of raw materials. For thousands of years, people have used types of lye for making soap and tanning hides. They burned certain hardwoods at a very high temperature to make white ashes. Water, mixed with a bit of baking soda, then was used to penetrate the ashes and remove the lye that they contained. When the ashes were filtered out, the water would hold enough lye for purposes such as dissolving the fat left on animal furs or mixing with other ingredients to make body soap.
This is one of many poisonous products that can be found in homes and that should be kept out of the reach of children and used only as directed. For example, a person should carefully follow the directions to clean sterling silver with a lye-based polish, because even the fumes can be dangerous. Lye-based products such as drain de-cloggers and paint stripper should never be used without proper air circulation.
Caustic lye products pose other dangers to surfaces. They can dissolve substances to the user's advantage, such as hair clogs in a shower drain, as well as to the user's detriment, such as the adjacent shower curtain. In fact, these products can damage and corrode paint, metal, cloth, plastic and especially skin. It can be so reactive that, in its solid form, it should be kept away from metals, such as aluminum, and the open air. It usually is non-combustible when dry, but it could ignite and cause a fire when mixed with water.
What Is Lye Used For?
Lye has a wide variety of different uses, ranging from everyday household applications to food curing agents to animal hide tanning. Initially, lye would be drawn out of the ashes of certain hardwoods in a long and arduous process. Only a small amount of lye would be available for tanning hides and making soap in the early days. Now, modern manufacturing produces lye in many different forms. Lye comes in flakes, powders, granules, pellets, liquids, microbeads, or solid forms. Depending on how it is produced, it can be used for a variety of applications, including:
- Hand soap
- Pretzel cure
- Draining agent
- Paint stripper
- Silver polish
- Lye rolls
- Laundry detergent
- Oven cleaner
What Does Lye Do?
Lye is a highly reactive alkali, and it is a hazardous chemical that, in large quantities, can cause significant damage. However, small and regulated amounts can be used as food curing agents. This highly reactive alkali is soluble in water and produces caustic base solutions. Practically, it is used to quickly dissolve sticky and greasy substances that are difficult to remove, such as grease or clogged drains.
Is Lye Dangerous?
Despite being used in food curing processes, lye is extremely dangerous. Lye can be included in food processing because it is carefully regulated and combined with other ingredients. It is also because the base formula for lye has changed slightly over the years. Lye began as potassium hydroxide, and now, lye is generally sodium hydroxide instead. Lye in food processing much be stringently documented and monitored.
Lye in other applications is just as dangerous. Lye is known for its quick and powerful ability to dissolve fat and grease. It can also severely affect human tissue, ruin surfaces, and paint. While it may effectively unclog the drain, it is possible that if the drain is old, it could continue to eat through the rest of the pipe, causing an entirely different issue. Before using lye in your drains, consult with a plumber.
What If Lye Gets on You?
Lye can cause severe damage to your body if you come into contact with the hazardous material. Contact emergency services immediately for help. As you wait, remove any contaminated clothing. Wipe any excess away lye from the affected area.
To prevent contact with lye, wear protective equipment and always work in a well-ventilated area. Never work with lye alone. Lye is a highly reactive alkali. The slightest bit of water in contact with lye can cause a violent reaction. A large amount of water in contact with lye can cause water to boil. Lye is also corrosive. Despite it being in a sealed container, it can still be dangerous without you knowing it. Depending on the container and the amount of time it has been stored, the container could be compromised.
Can Lye Cause Injuries?
Because lye is a highly reactive and corrosive material, if you are not careful, it can also cause serious injuries. Always work with another person and follow safety protocols carefully. Some injuries caused by contact with lye include:
- Chemical burns
- Esophageal stricture
- Tissue damage
- Lung damage
- Hypovolemic shock
- Pulmonary insufficiency
Is Soap Made of Lye?
A common misconception about lye and soap is that soap is made from lye, and the assumption is incorrect. Instead, soap is made with lye. This update is good news because people can become very bewildered to think such caustic ingredients are in their self-care routines.
Soap is made through a process called saponification. In this process, lye and triglycerides combine. During this combination, the lye corrodes the fat in the molecules and connects with other parts. The resulting chemical reaction creates both soap and glycerin. Neither of the original ingredients remains in a chemical reaction, only the results of the reaction and the byproducts. Therefore, both the lye and the triglycerides are removed from the end product you use as soap.
Many people are concerned about the use of lye in their soap-making process. This concern is primarily based on a misunderstanding. The truth is that all true soap is made with lye in the process. If it is not made with lye in the process, it is something other than soap.
Many people are unaware that chemical reactions need to happen for your skin to benefit from soap or a soap-like product. Without the reaction, your skin might not be cleansed or moisturized by that product. Moisture retention and cleansing properties are integral for maintaining the health of your skin.