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Types of boric acid-based termiticides

Our company manufactures and sells boric acid-based ant repellents and preservatives. Here is a summary of the borate preservatives, which are still not well known.
There are currently two types of boric acid-based termite repellents available in Japan (more than three if you break them down): SOUFA (sodium polyborate) and DOT (disodium octaborate tetrahydrate).
The first one is SOUFA, which we sell. It is a boric acid-based termite repellent produced by a special method called sodium polyborate.
The other is Disodium Octaborate Tetrahydrate, which is used worldwide.
Disodium octaborate tetrahydrate (DOT) is distributed under the names Tim-bor and Bord Defense. It is manufactured by the Rio Tinto Company in the United States. However, it is difficult for the general public to enter the market, as it is mostly distributed by vendors.
Ecoboron (Eco-Powder) is manufactured by adding an additive to disodium octaborate tetrahydrate. Disodium octaborate tetrahydrate does not have a high solubility in water, so the concentration of disodium octaborate tetrahydrate is maintained at a high level with additives to compensate for it. It probably also contains a surfactant. This increases the rate of penetration into the wood.
Other companies that can be found by searching the internet include Nippon Borate. This company imports and sells disodium octaborate tetrahydrate. They also sell sealants and other products manufactured independently.
In addition, there is Nippon Borate Co. They import disodium octaborate tetrahydrate and sell it. They also sell sealant etc. which they manufactured by themselves.
The difference between SOUFA and disodium octaborate tetrahydrate

Now let’s consider the difference between SOUFA and disodium octaborate tetrahydrate in concrete terms.

Solubility of SOUFA and disodium octaborate tetrahydrate.

SOUFA: 25°C, 23% (*approx. 16% concentration for products sold to the public)

Disodium octaborate tetrahydrate: 20°C, 9.5%.

Boric acid: 20°C, 4.67%.
The solubility of SOUFA is about twice as high as that of SOUFA, but the temperature conditions are different, so it’s hard to make an exact comparison. Originally, the boric acid type termiticides are supposed to be soaked into the wood, so it is desirable that they are easy to dissolve in water.

These are all concentrations that can be maintained at the indicated temperature. As the temperature drops, the saturation concentration changes, and as the temperature rises, more boric acid dissolves.

Flame-retardant (all cellulose)
SOUFA> Disodium octaborate tetrahydrate

SOUFA is a product originally developed as a flame retardant agent for wood. Therefore, it has a high level of flame resistance.

Effect on termites

Unverified: not expected to change.

Boric acid is toxic to insects in general and is expected to have a high ant control effect. The higher the concentration, the more desirable it is, and according to our tests we think a concentration of 10% or more is desirable. In our tests, we believe that a concentration of 10% or more is desirable. Disodium octaborate tetrahydrate can be certified by transporting the powder to the site and dissolving it in hot water at the site. The concentration of disodium heptaoxide tetrahydrate is 9.5% at 20°C. Therefore, from early autumn to early spring, it is necessary to operate the heater that keeps the temperature of the solution constant for use at the construction site. Therefore, it is not so easy to handle. We are sometimes consulted by contractors who use disodium octaborate tetrahydrate for ant repellent construction that it is difficult to handle.


No toxicity to humans. Generally about the same level as salt.

SOUFA has undergone various safety tests. As a result of those tests, we can say that there is no acute toxicity to humans. We did not find any test results for disodium octaborate tetrahydrate, but we did not find any acute toxicity of the type of boric acid used as a raw material. The safety of additives such as surfactants and phosphates could not be confirmed by us. Please check the published information of each company individually.

Because only water evaporates when SOUFA is dried, it has no adverse effect on the human body. The effects of additive evaporation of disodium octaborate tetrahydrate ant repellents on the human body are unknown.

Duration of Effects

As long as it doesn’t get wet, it’s permanent.

Boric acid is an inorganic substance. Inorganics do not volatilize. Therefore, once it settles on wood, boric acid does not disappear. However, since it is water-based, boric acid will dissolve out of the wood under conditions such as water exposure, rain, extremely high humidity and condensation.


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