What is sodium metasilicate?

Sodium metasilicate is a colorless or white chemical compound that forms an alkaline solution when mixed with water. It is a component in high-temperature adhesives and in insulation boards for fire protection. Sodium metasilicate is also marketed as a phosphate-free green cleaner.

Sodium metasilicate is poisonous if ingested. It irritates the eyes, skin and lungs, so when working with sodium metasilicate, wear eye protection, a dust mask and clothing that covers the body. Sodium metasilicate is effective as a detergent because it binds to minute particles, causing them to clump together. Sodium metasilicate is also known as waterglass or liquid glass.