Shin-Etsu Chemical develops the “RADIBARRIER” series of liquid silicone rubber with radiation-shielding properties

Application of this newly developed product expected to greatly help in the decontamination efforts in the disaster-stricken areas of Japan


Shin-Etsu Chemical Co., Ltd. (Head Office: Tokyo, President: Shunzo Mori) has developed a liquid silicone rubber material, called the “RADIBARRIER* Series,” which acts as a shield against radiation.

After the accident at the Fukushima No.1 Nuclear Power Station in the wake of the Great East Japan Earthquake, decontamination of radioactive substances is under way mainly around the area of Fukushima Prefecture. However, there are many places that are difficult to decontaminate, such as roofs, under flooring, and cracks in concrete and asphalt, due to structural and other problems, and this has become the cause of rising amounts of air-transmitted radiation being present both indoors and in surrounding areas.

Shin-Etsu’s RADIBARRIER Series of liquid silicone rubbers was developed by mixing a radiation-shielding material with liquid silicone rubber to add the function of attenuating gamma (γ) rays. The accumulation of long-term exposure to doses of radiation can be greatly reduced by using this product in places that need to decontaminate radioactive materials such as private residences and facilities where radioactive materials are stored.

The “RADIBARRIER Series” consists of “RADIBARRIER 101,” which has low viscosity and can be poured into a small opening, and “RADIBARRIER 102,” which has high viscosity and is a suitable sealant for vertical and other surfaces. After both of these new products are hardened at room temperature, the new products demonstrate superior heat resistance, cold resistance and weather resistance – characteristics that are similar to those of existing silicone rubbers – and they are superior in long-term reliability. In addition, application products such as shielding silicone rubber sheets (“RADIBARRIER sheets”), which are molded in the shape of sheets, and shielding storage containers are already developed.

The research and development of this product was initiated based on a request from EARTH Corporation, a Japanese company, headquartered in Koriyama City in Fukushima Prefecture, which performs decontamination of radioactive materials and measurement / analysis of environment. With regard to the development process of this product, performance verification of this product has been carried out in collaboration with major general contractor companies and Fukushima Prefecture’s local governments. For example, in the case of gamma radiation that emanates from Cesium 137, Shin-Etsu’s new product achieved about 70% radiation attenuation with a sample thickness of 3cm.

In addition, silicone rubber’s superior characteristics of weather resistance and durability are widely recognized in such application areas as sealants for construction applications and electronics components, and it is most suitable as a material for applications that require long-term reliability. Furthermore, because the RADIBARRIER Series do not contain environmentally hazardous substances such as lead, it has the big advantage of being burnable in incinerators after use.

Shin-Etsu Chemical has also been successful in the development of a prototype that has an even greater radiation-shielding effect. Shin-Etsu is also focusing on furthering the goal of using this radiation-shielding material as an alternative material to lead, which is presently used as a radiation-shielding material in such application areas as nuclear power-related facilities and in the medical field.

Sales of the radiation-shielding “RADIBARRIER Series” in areas designated by the national government as Special Decontamination Areas and Intensive Contamination Survey Areas will be handled by EARTH Corporation. Shin-Etsu Chemical will serve as the service window in all other cases.

Going forward, Shin-Etsu Chemical will continue to support the restoration of the disaster-stricken areas of Japan through our key materials and technologies.

* “RADIBARRIER” is in the process of being registered as a trademark.

For inquiries about this matter, please contact


    • Shin-Etsu Chemical Co., Ltd. Public Relations Dept. Tetsuya Koishikawa or Hideki Aihara
    • TEL: 03-3246-5091, or from outside Japan: 81-3-3246-5091 
    • FAX: 03-3246-5096, or from outside Japan: 81-3-3246-5096