Zinc borate is an inorganic compound that presents as a white crystalline powder. It’s insoluble in water. Several variants of zinc borate exist with different zinc/boron ratios and water contents. Zinc borate has low toxicity and isn’t considered hazardous. The fire-retardant properties of zinc borate form the foundation for many of its uses in industry. Still, it also has many other useful characteristics. Zinc borate is found in plastics and cellulose fibres, paints and fungicides. Bisley supplies zinc borate to diverse sectors worldwide. 

Applications of Zinc Borate

As we mentioned, zinc borate is a versatile compound with many different applications. We give a short description of some of these applications below. 

Paints, Pigments And Adhesives

The flame-retardant and smoke suppressing properties of zinc borate define how it’s primarily used in paints, adhesives, and pigments. In combination with zinc phosphate or barium phosphate, it acts as a corrosion inhibiting pigment. 


Halogen containing systems: Zinc boride acts as a char promoting agent. The zinc boride forms a protective layer of glass. Here, zinc borate works with antimony trioxide and alumina trihydrate. Zinc borate also has anti-drip properties.  

Halogen-free systems: Zinc borate works with alumina trihydrate, magnesium hydroxide, red phosphorus or ammonium polyphosphate to do the same. As the plastics burn, a porous boron ceramic is formed, protecting the layers beneath. Halogen-free systems show better flame retardant properties. 


Polyamide plastics have many useful properties. The heat, smoke and toxic gas from the burning of polyamides hinder their use. As polyamides consist of strings of polymers, the same flame retardant and smoke suppressant properties apply. Phosphinate-based and halogen-free electrical insulator plastics use zinc borate. Alumina trihydrate, magnesium hydroxide and red phosphorus work with zinc borate in these plastics. The zinc boride acts as a char promoting agent and suppresses afterglow. 


The agriculture sector uses zinc borates to increase crop yields and prevent plant diseases. Some micronutrient formulations also use it in their fertilisers.  

Other Uses

Zinc borate is also used as a flame suppressant in cellulose fibres, paper, rubbers and textiles. Other uses include a wood treatment for fungus control and to improve the friction properties in lubricants. It also finds use as an adhesive in bonding aluminium foil and fibreglass. This compound even finds use in insulating ceramics as flux. It also has the effect of reducing firing time and temperatures for ceramics. For this reason, it’s often used in the manufacture of bricks and porcelain.


Zinc borates have many uses. The flame-retardant and smoke suppression properties make it ideal for polymers and polyamides. It also finds use in paper, rubbers and textiles for the same characteristics. The agricultural industry uses zinc borate as plant nutrition. It also finds use as a fungicide and to prolong the life of the wood. It’s beneficial in cables and insulators and as an arc suppressant. It even finds use in lubricants to improve friction properties. This versatile mineral has uses in almost every industry.