As a country of volcanoes, Japan is also a veritable land of hot springs, and many Japanese people love to soak in hot springs and home baths, and often use various bath salts and bath blocks in baths, and simulate a natural hot spring environment by increasing the salinity and mineral content of the bathing water. The most striking feature of the Japanese bath bomb is that it releases a large amount of carbon dioxide through a chemical reaction, mimicking a natural carbonated hot spring, and at the same time adding fragrance to enhance the soothing effect.
 
Kao is one of Japan's largest manufacturers of daily chemical products, with a product line that includes all kinds of cleaning products, paper products, cosmetics, and more. Since 1983, Kao has launched the "バブ" Bub brand bath block, which is a representative product of Japanese bath bombs, and has been very popular with Japanese consumers since its release, and has been one of the best-selling bath agents in Japan. Although Bub was invented much earlier than LUSH's bath bombs, the product is significantly different, and compared to LUSH, which focuses on appearance and fragrance, Bub is more modest and is mainly sold in Japan and neighboring countries in East Asia.
 
Each Bub bath block weighs about 40g, is small in size, and the main ingredients are baking soda and fumaric acid. Fumaric acid is more acidic than citric acid and can provide a faster reaction rate and release more carbon dioxide, and the sodium fumarate produced by reacting with baking soda has a fruity taste that can add fruity flavor to the water body. The PEG6000 polyethylene glycol is used as a binder in the Bub formula, and the product texture is denser, rather than the rough, loose appearance of the LUSH bath bomb, which is more hard and less brittle, and is packaged in candy-type plastic packaging, like a large effervescent tablet, which is very portable.
 
The decorative ingredients of Bub are relatively simple, only a small amount of pigment is added, the water color is transparent, and the fragrance is made by a small amount of flavor ingredients, and no surfactant ingredients are added, which is milder and safer, and does not have a cleaning effect. Despite its modest appearance, Bub's efficacy is superior to LUSH. After the bath block is put into the water, a large number of carbonic acid bubbles will be quickly generated, and the dense carbonic acid bubbles will be wrapped on the surface of the body, which has a certain heat retention ability, and at the same time, due to the instability of the bubbles, it will gently stimulate the skin when it bursts, producing a feeling like a massage, making the human body feel relaxed. However, the carbonic acid bubbles dissipate quickly, so you can soak your body in water before putting it into the bath. In addition, Japanese people are accustomed to taking a shower to cleanse their bodies before taking a bath, and the carbonated bubbles will dissipate faster when encountering alkaline substances, so do not use soap cleaning products at the same time.
 
Another major feature of the Bub bath block is the addition of magnesium sulfate, sodium sulfate and other ingredients to achieve the effect of simulating a natural hot spring. Magnesium sulfate is commonly known as salt discharge, external use of high-concentration moist heat compress can reduce pain, used in bathing when the dilution is higher, although the effect is not as obvious as external application, but still has a certain soothing and relaxing effect, is also one of the most commonly used ingredients in bath salts.
 
It should be noted that each Bub bath block is recommended to add 150L-200L of warm water to use, the long oval single bathtub commonly used in China is generally about 1.5m long, and the water storage capacity is more than 300L, which is larger than the storage capacity of the Japanese bathtub, if you want to achieve a better use effect, you can use two at the same time.
 
Bub's fragrance is also very Japanese, mainly using light botanical notes such as rose, orange, mint, and cypress, which can provide a mild soothing sensation and is friendly to those who are sensitive to fragrance. Bub bath block is relatively inconvenient to buy in China, about 2 yuan per piece in Japan, and about 4 yuan per piece in China, which is a cost-effective daily bathing choice.