Jul 22 2015

Borax: Unsafe for Pets

By Dr. Angela Damant, D.V.M., B. Sc. (HH)

What Is Borax?

Borax is a common household and commercial chemical. It is a natural mineral called sodium tetraborate decahydrate. Borax also is known as sodium borate, sodium tetraborate or disodium tetraborate. Borax is found in many cleaners, flame retardants and fungicides.

Borax cleans by converting some water molecules to hydrogen peroxide (H2O2). The pH of borax is 9.5 (basic) and the boron, salt, and/or oxygen of boron inhibit the metabolic processes of many organisms.

Risks Associated with Borax

Borax is natural but that does not mean it is automatically safe. Borax isn’t just toxic to bugs, plants and fungi, it’s also toxic to pets and to people as well. The estimated lethal dose (ingested) for adults is 15-20 grams (exposure to borax may impair fertility or cause damage to an unborn child at lower doses); less than 5 grams can kill a child or pet.


Within two hours of ingestion of sodium borate, your pet may experience symptoms including vomiting, diarrhea, stomach pain, drooling and excessive thirst. Contact with borax can cause redness or irritation of the skin and eyes. Inhalation of borax by your pet can cause coughing or shortness of breath.


Chronic exposure of your pet to borax results in red and peeling skin, seizures, kidney failure and even death.

According to several leading veterinary specialists including Dr. Tina Wismer DVM, DABVT, DABT from ASPCA Poison Control Center and Dr. Kathy Tater DVM, MPH, DACVD, CPH:


Borax is a GI and skin irritant. Borax is well absorbed through abraded tissue and the GI tract. Small amounts can cause vomiting. Repeated use or large amounts can cause renal failure. They do not recommend this as rinse.

In Summary

Borax is a dangerous poison. Poisoning from this chemical can be acute or chronic. Chronic poisoning occurs in those who are repeatedly exposed. For example, in the past, Borax was used to disinfect and treat wounds. Patients who received such treatment over and over again got sick, and some died.

Now, none of these risks mean that you shouldn’t use borax and you will find risks associated with all cleaning products. However, you do need to be aware of product risks so that you can use those products properly. Don’t use borax around food, keep it out of reach of children and pets, and make sure you rinse borax out of clothes and completely off of surfaces before use.




Goldfrank LR. Ed. Goldfrank’s Toxicologic Emergencies. 8th ed. New York, NY: McGraw-Hill; 2006.
Cain WS. Sensory and associated reactions to mineral dusts: sodium borate, calcium oxide, and calcium sulfate. J Occup Environ Hyg. April 2004; 1(4): 222-36.
Matsuda K Toxicological analyses over the past five years at a single institution. Rinsho Byori.Oct. 2004; 52(10): 819-23.

National Pesticide Information Center (npic@ace.orst.edu or 1.800.858.7378).

Environmental Protection Agency.

Dr. Tina Wismer DVM, DABVT, DABT from ASPCA Poison Control Center

Dr. Kathy Tater DVM, MPH, DACVD, CPH

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