What is sodium hydroxide (NaOH)?

Sodium hydroxide is sometimes called caustic soda or lye.  It is a common ingrediet in cleaners and soaps.

At room temperature, sodium hydroxide is a white, odorless solid.  Liquid sodium hydroxide is colorless and has no odor. It can react violently with strong acids and with water.  Sodium hydroxide is corrosive.  NaOH can react with moisture from the air and may generate heat as it dissolves.  This heat can be enough to cause a fire if it is near flammable materials.

Sodium hydroxide is useful for its ability to alter fats.  It is used to make soap and as a main ingredient in household products such as liquid drain cleaners.  Sodium hydroxide is usually sold in pure form as white pellets or as a solution in water.

What are some uses of sodium hydroxide?

Sodium hydroxide is used in bar soaps and detergents.  Sodium Hydroxide is also used as a drain cleaner to unclog pipes.

Around 56% of sodium hydroxide produced is used by industry, with 25% of NaOH used in the paper industry.  Some other uses include fuel cell production, to cure food, to remove skin from vegetables for canning, bleach, drain cleaner, oven cleaner, soaps, detergent, paper making, paper recycling, aluminum ore processing, oxide coating, processing cotton fabric, pickling, pain relievers, anticoagulants to prevent blood clots, cholesterol reducing medications, and water treatment.

How might you be exposed to sodium hydroxide?

In the home, some household items like soaps or cleaners contain sodium hydroxide.  Accidental ingestion or skin contact with these cleaners could cause harmful exposure.

Some industrial workplaces use sodium hydroxide.  Here are some workplace exposure limits to NaOH in the air.

Workplace air exposure limits:

OSHA: The legal airborne
permissible exposure limit (PEL) is 2 mg/m³ averaged over an 8-hour work shift

NIOSH: The recommended airborne
exposure limit (REL) is 2 mg/m³ which should not be exceeded at any time

ACGIH: The threshold limit value
(TLV) is 2 mg/m³ which should not be exceeded at any time

How can you protect your family from exposure?

• Follow all precautions and instructions on product labels.

• Store and keep cleaning products out of the reach of children.

• Keep cleaning products in their original packaging.

• Wear latex or nitrile gloves when using products containing high concentrations of NaOH.

• Wear long sleeves and pants that cannot be degraded or deteriorated by sodium hydroxide to protect your skin.  Remove clothes carefully if they get wet to avoid spreading the sodium hydroxide on your skin.

What are potential harmful effects of sodium hydroxide exposure?

Sodium hydroxide is a potentially dangerous substance.  It can hurt you if it touches your skin, if you drink it or if you breathe it.  Eating or drinking sodium hydroxide can cause severe burns and immediate vomiting, nausea, diarrhea or chest and stomach pain, as well as swallowing difficulties. Damage to the mouth, throat and stomach is immediate.  Breathing it can cause severe irritation of the upper respiratory tract with coughing, burns and difficulty breathing.

The harmful effects of sodium hydroxide depend on several factors including the concentration of sodium hydroxide, length of time exposed, and whether you touched it, drank it or inhaled it.  Contact with very high concentrations of sodium hydroxide can cause severe burns to the eyes, skin, digestive system or lungs, resulting in permanent damage or death.  Prolonged or repeated skin contact may cause dermatitis.  Repeated inhalation of sodium hydroxide vapor can lead to permanent