Pursuing the unlimited potential of seawater to establish the seawater business.

Since we made our capital participation in Tateho Chemical Industries as an opportunity to develop a business using magnesium extracted from seawater, we have been pursuing the potential of seawater where various materials exist. As a long-established manufacturer and seller of gases produced by separating air, Air Water believes that ideal business opportunities can be found where there is air, water and also where they are mixed together. We create businesses that make effective use of seawater resources, such as salt for business and household use that we boast the largest market share in Japan and value-added magnesia products utilizing crystal control technology.


Our subsidiary Nihonkaisui Co., Ltd. is the leading producer of salt in Japan. Our salt is made by a process which is a refined version of the traditional process in Japan, where concentrated saltwater is made from seawater and then boiled down to form salt crystals. We deliver salt in a variety of forms, including salt for business and household use and artificial saltwater for breeding saltwater fish.

Environmental products

Our subsidiary Nihonkaisui Co., Ltd. has been expanding its business into broader areas focused on environmental products, such as water and soil treatment adsorbents and magnesium hydroxide utilizing seawater resources and technologies. In addition, our subsidiary Aquaintec Corporation has been contributing to the development of safe and comfortable communities with its technology to regenerate aged underground pipes without digging up the ground.

Food and agriculture

Our subsidiary Nihonkaisui Co., Ltd. uses seawater resources to manufacture and sell potassium chloride, which is one of the three major fertilizers required for the growth of plants. We also commercialized bittern generated in salt production processes as a food additive. We offer high-quality seaweed products under the brand of Urashima Nori as well as Italian food ingredients and seawater-derived mineral water.


Under the integrated cogeneration power system of woody biomass and natural gas, the Ako Plant of Nihonkaisui Co., Ltd. makes effective use of the steam and electricity generated for its own purposes and also sells some of the electricity externally. By converting fuel from conventional fossil fuel (PC coal) to woody biomass and natural gas, we have also successfully reduced CO\( \sf _2 \) emissions. Furthermore, we are contributing to the promotion and development of forestry in neighboring areas and expansion of employment opportunities by continuously using large amounts of wood chips.


Our subsidiary Tateho Chemical Industries supplies high-functional and high value-added magnesium oxide (magnesia) powder and ceramic products using seawater and bittern generated from seawater as raw materials to various industries. The company produces a variety of magnesium oxide (magnesia) with different properties by utilizing its unique “crystal control technology” and “fining technology” which generate high-quality and high-purity products.
Magnesium oxide with a particle size of several millimeters is used as a refractory for furnaces that melt iron due to its low reactivity with iron. On the other hand, magnesium oxide with a few microns is used for manufacturing of electrical steel sheets including a reaction process of magnesium oxide with iron.