Making products using only konjac

No preservatives, antibacterial agents, or petroleum-derived ingredients are used at Yamamoto Farm to produce products using only konjac.
As you can see below, there are no preservatives, antibacterial agents, or petroleum-derived ingredients detected in our konjac products.

No preservatives or antibacterials

5-Chloro-2-methyl-4-isothiazolin-3-one is an antimicrobial agent called methylchloroisothiazolinone and 2-methyl-4-isothiazolin-3-one is called methylisothiazolinone.
Paraoxynebenzoic acid is a common preservative called a paraben.
The absence of these ingredients indicates that our konjac sponge does not contain any antibacterial or preservative agents.

Petroleum originated components not used.

Phthalic acid is used as a plasticizer to soften plastic products.
Bisphenol A is used as an ingredient in plastics.
The fact that these ingredients are undetectable indicates that our konjac sponge does not contain any chemical ingredients.


Yamamoto Farm wants our customers to be able to use our products with confidence, so we label all of our ingredients on our packaging.

Konjac sponge is not a "cosmetic" product and we are not obliged to label all the ingredients.
Some konjac sponges made in China and Korea contain antibacterial agents, but do label their packaging as "100% natural and safe for babies".
A survey of foreign-made konjac sponges distributed in Japan confirms the use of methylisothiazolinone.

This methylisothiazolinone is not allowed to be used in products that are left on, such as skin care and makeup products.These antimicrobial agents are approved for use in a limited range of products that are rinsed off immediately, such as shampoos and rinses.

Many antimicrobials can be very irritating to babies and those with sensitive skin, and in some cases, they can cause skin problems.

Cleaning power of konjac sponge

Konjac sponges have a feature that the slightly alkaline ingredients that seep out of the sponge neutralize and decompose weakly acidic stains and dirt from the pores and wash them away.
The real konjac sponge, which has been handed down in Japan, is manufactured using only konjac.
Many of our konjac sponges are used by people with sensitive skin.
In order for them to wash off dirt without irritating their skin, we believe that the pH should be between 8.0 and 9.0, which is mildly alkaline.

Therefore, we measured the differences in the PH values and clarified the differences in the characteristics of the products.
We compared the PH values of konjac sponges made by our company, Korea and China, and found the following results.

Konjac sponge from Yamamoto Farm pH8.4

Mildly alkaline.
Gentle on the skin with excellent cleaning power.
Made using only konjac and suitable for sponges.

Made in Korea pH6.7

It is neutral and has weak cleaning power. Neutral "konjac" is not considered and has a shining white color that is not found in nature.
This may be due to the use of other ingredients and antibacterial agents.
It is clear that "ingredients other than konjac" are used in this product, but there is no label for them.

Made in China pH9.5

It has a high cleaning power, but it is also very hard on the skin. It is barely in the weak alkaline range, but it can be very irritating to the skin and may cause skin problems for some people, especially those with sensitive skin. Would not be recommended for those with sensitive skin.

※Specific product names are being withheld.

Why is the konjac sponge good for your skin?
-It washes out smooth and moisturized.

The surface of your skin has a stratum corneum that prevents bacteria from entering and water from evaporating, keeping your skin fresh.
However, as the skin becomes dry, gaps form in the stratum corneum layer, making it easier for moisture to evaporate and for external stimuli to enter the skin. The stratum corneum is as thin as 0.02 mm, and even the slightest stimulus can easily cause damage to the skin, making it prone to skin problems.

Therefore, rubbing too hard causes inflammation, which breaks down the barrier of the stratum corneum and makes the skin even drier and more irritated, leading to chronic eczema.
The surface of the konjac sponge, which is full of water, is covered with a film of water.
When you gently stroke your face, the soft, 100% natural fibers and the water film that surrounds it gently wash away dirt without damaging the stratum corneum of your skin.