How Does Borate in Cellulose Insulation Prevent Pests?

Are insects in your home a major concern? There are ways to kill or repel them, and some of the solutions may surprise you — like your home insulation. 

Borate or borax in cellulose insulation can either kill bugs or work to repel them, helping to keep your home free from pesky pests. In today’s blog post from Valley Insulation, we explore how borate-treated insulation repels insects in your home for pest prevention. 

Related Post: Valley Insulation Explains How We Install Cellulose Insulation

What Are Borax and Borate? 

Borax (borate) is a naturally occurring substance first found around 700 B.C. in dried lake beds in Tibet. It wasn’t manufactured for widespread consumer use until the 1800s. Today, borax is typically found in white powder form, and it is most often used in laundry detergents and other household cleaning products. Borax is a mineral and salt combination derived from boric acid.

Borate is a colorless crystal or powder that dissolves in water. It’s typically used as an ingredient in insecticides, antiseptics, flame retardants, and neutron absorbers in nuclear reactors. 

Why Cellulose Insulation?

Borate is added to cellulose insulation during the manufacturing process. Our teams primarily use cellulose insulation as loose fill to insulate attics, lofts, and wall cavities. Nu-Wool, the cellulose insulation used by Valley Insulation, is made up of 86 percent recycled content, with 68 percent of that coming from recycled newspapers. While this is an excellent way to reduce the carbon footprint, it has to be mixed with borate to increase flame resistance and combustion retardancy. 

Related Post: How Cellulose Insulation Is Fire Retardant

Aside from killing and repelling bugs, borate is recognized as an effective Class 1 flame retardant additive, eliminating smoldering combustion. Borate is also an anti-fungal, reducing the risk of mold and fungus growing in the damp, darker areas of the home where insulation is typically used. 

Borate is not only colorless, but it is also odorless. Thus, it does not contribute to odors in the home. 

Related Post: Amazing Cellulose Insulation Facts

How Borate Attacks Insects 

Borate, when used as a repellent, will keep the home naturally insect-free. There are two ways to combat bugs in the home: repelling and exterminating. The borate used in the insulation manufacturing process can do both. 

Borate, when added to cellulose insulation properly, can repel insects. However, if there’s a breach in the home and a bug does enter, it can be exterminated through contact with the borate. 

Borate in powder form is present throughout cellulose insulation. The insect walks through the powder, which clings to the legs and body of the insect. The powder absorbs into the body, affecting the metabolism and exoskeleton. When the insect realizes the powder is on it, the bug will attempt to clean itself, ingesting the poison. Borate is only effective on bugs that groom themselves. This includes ants and cockroaches. 

Borate, however, will not exterminate ticks, bed bugs, beetles, centipedes, flies, moths, and hornets. You will need to contact a professional pest control company to eliminate those. 


The professionals at Valley Insulation make safety a number one priority, not only for them but for you as well. We adhere to the highest safety standards when installing and removing insulation, ensuring that you and your family are safe. If you’re seeing more insects than usual, or your home isn’t heating or cooling like it used to, contact us to see if your home needs new cellulose insulation. 

Borate Insulation in Cincinnati

Talk to the experts at Valley Insulation, serving the Greater Cincinnati area since 1977, for cellulose insulation installation. Contact us online or call 513.353.4100 for more details on what we offer.

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