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Sodium Hydroxide (Lye) Safety

Apr 21, 2014

Used many years ago in soaps, sodium hydroxide – also known as lye – is still a widely used chemical today. Its uses range from food processing to petroleum refining, but it can be a very dangerous chemical. Here we’ll examine its usual uses, and the specific properties that make sodium hydroxide a threat to safety.

(Photo: Sodium Hydroxide 6mol Corrosive Lab Chemicals by Maticulous)

What Is Sodium Hydroxide and how is it Used?

Sodium hydroxide is an odorless, inorganic compound that serves as a metallic base for many types of chemicals, particularly in the paper and textiles industries, food processing, soaps, detergents and cleaners. Made from the chemical formula NaOH - an alkali that is made from a hydroxyl ion attaching to a sodium ion – sodium hydroxide is a white solid that can come in several forms, including pellets, flakes, granules and prepared solutions. Solutions mixed using sodium hydroxide come in different concentrations, the most common being a 50 percent saturated solution with water.

The Benefits of Sodium Hydroxide

Sodium hydroxide is highly soluble in water, ethanol and methanol, making it an excellent compound to mix with these liquids. It is also a deliquescent, meaning it has strong absorption capabilities, so it easily and quickly absorbs moisture and carbon dioxide in the air. Because of these chemical attributes, major uses for sodium hydroxide are:

  • As an aqueous solution
  • Use in the chemical industry
  • Creation of sodium salts
  • Detergents
  • pH regulation
  • Aluminum production
  • Increasing the alkalinity of a mixture
  • Neutralizing acids
  • Food processing (peeling vegetables, processing cocoa, soaking olives)
  • Removing impurities from oil
  • As an additive in drain declogging formulas
  • Part of the paper-making process

Hazards Associated with Using Sodium Hydroxide

As stated previously, sodium hydroxide is highly caustic, but it is not currently classified as a carcinogen. However, it can cause serious damage when not handled safely.

The two most common ways to become injured by sodium hydroxide is either by contact (skin or eyes), or by inhaling a vapor containing high levels of the compound. The following injuries can occur when coming into direct contact with undiluted sodium hydroxide:

  • Ulceration of the nasal passages
  • Irritation of the skin, eyes, lungs or nasal passages
  • Eye and skin burns, sometimes severe
  • Esophageal burns if swallowed
  • Blindness

Best Practices with Sodium Hydroxide

The wearing of protective gear can help prevent serious injury from sodium hydroxide. Here are some suggestions on what to wear both at home and at work:

  • Respirator
  • Boots
  • Long rubber gloves
  • Industrial aprons
  • Overalls
  • Chemical safety goggles
  • Face shield
  • Use of an eye wash fountain in work places
  • Use of quick-drench systems in work areas

In addition to protective gear, NIOSH recommends that the maximum exposure to sodium hydroxide should be no higher than 10mg.

Safety Comes First When Handling Sodium Hydroxide

Sodium hydroxide is present in so many items it is virtually unavoidable. While it does not pose a large threat to the vast majority of people, it is a chemical that can cause serious damage in certain circumstances. By paying attention and taking the necessary steps to be physically protected, you can make sure your exposure doesn’t leave lifetime damage. Learn more about sodium hydroxide and more by visiting our online MSDS library.


Leave a comment
  1. james | Apr 22, 2017
    No doubt it will be very useful for Kccatl Friends my future projects. Would like to see some other posts on the same subject! 
  2. smith | Apr 22, 2017
    Sodium Hydroxide (Lye) Safety is an interesting article that can be a reference for sprei anti air
  3. Paul worrall | Apr 18, 2017
    Hi guys, just a quick question. Me and my family are on holiday in lanzarote and we have been here for 3 days. We have been in the pool on the first day and no problem. Second day we had the owners pool cleaners around and they had used sodium hydroxide to clean the pool. They did say we could go straight back in the pool but we left it for around an hour or so. Because we have kids with us we gave them T-shirts to wear in the pool to protect them from the sun. After about 20mins we found that they were having problems with there eyes and the yellow colouring to the T-shirts we got them out the pool. Just abit cautious to go back in. This morning we had another guy in to hoover the pool and he also used sodium hydroxide. Is it safe to go back in and how long do we leave it for? Thanks msdsonline

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