Sodium hydroxide, also known as lye or caustic soda, is a widely used chemical in both household and cosmetic products. In skin care, it appears as white, odorless crystals and is found in items such as soaps, facial cleansers, lotions, makeup, hair dye, and even nail care products.
Is Sodium Hydroxide Safe?
- Low concentrations: In beauty and skin care products, sodium hydroxide is generally safe. The amount used is small and designed to be non-irritating for most users.
- High concentrations: Pure sodium hydroxide or high concentrations can cause chemical burns, severe irritation, or permanent skin damage. Ingesting or inhaling it is extremely dangerous.
- Cosmetic safety: Because skin care products only contain tiny amounts, you are highly unlikely to experience chemical burns or toxic effects. This means there’s no need to throw out your current products.
Why Do Skin Care Products Include Sodium Hydroxide?
- pH Balancing: Sodium hydroxide is highly alkaline, scoring 14 on the pH scale. It helps maintain the ideal pH in skin care products, which is crucial because human skin is slightly acidic, generally ranging from pH 4 to 7.
- Protecting the skin: Maintaining the skin’s natural acidity, or acid mantle, helps preserve moisture, defend against bacteria, viruses, environmental pollutants, and UV damage. A balanced skin pH supports overall skin health, preventing dryness, acne, irritation, and premature aging.
- Soap production: During saponification, sodium hydroxide transforms oils and fats into smooth, well-mixed soap. This process is essential for creating high-quality cleansers and other bath products.
Possible Side Effects
Although uncommon in cosmetics, sodium hydroxide may cause reactions in individuals with sensitive skin:
- Redness, rash, or hives
- Dryness, flaking, or increased sensitivity
- Mild irritation or inflammation
Patch testing: Always test a new product containing sodium hydroxide on a small area of skin (wrist or behind the ear) and wait 24 hours to check for adverse reactions. This precaution helps avoid unwanted skin issues.
Handling Precautions
- Never use pure sodium hydroxide on your skin.
- Gloves are essential when handling household products such as drain cleaners or oven cleaners containing sodium hydroxide. These products can cause severe burns or skin holes, along with irritation.
- Seek medical attention if you experience severe reactions, get sodium hydroxide in your eyes, or ingest it accidentally.
What Happens If You Have a Reaction?
- Skin irritation: Stop using the product immediately. Wash the area with plenty of water.
- Severe reactions: Get medical help right away if you experience swelling, breathing difficulties, or eye exposure.
- Ingestion: Sodium hydroxide can cause swelling in the throat, inflammation of the lungs, severe abdominal pain, or corrosive damage to the mouth and digestive tract.
Bottom Line
Sodium hydroxide is a key ingredient in skin care, primarily as a pH balancer and soap-making agent. While pure sodium hydroxide is dangerous, the tiny amounts used in beauty products are generally safe for most skin types. Those with sensitive skin should read ingredient labels carefully and perform patch tests to prevent irritation.
By understanding how sodium hydroxide works and why it’s included in skin care, you can use products confidently while maintaining healthy, balanced skin.