NOK Corporation (Headquarters: Shibadaimon, Minato-ku, Tokyo; Representative Director, Group Chief Executive Officer: Masao Tsuru; hereinafter referred to as “NOK”) will jointly exhibit with NiGK Corporation.(Headquarters: Kawagoe City, Saitama Prefecture; Representative Director and President: Masaru Oda; hereinafter referred to as “NiGK”) for the second consecutive year at “SEWAGE WORKS EXHIBITION '26 TOKYO,” held from Tuesday, August 4 to Friday, August 7, 2026, at Tokyo Big Sight (Koto-ku, Tokyo).

NOK will exhibit three products, including new products that contribute to improving workplace safety and addressing environmental concerns in the maintenance and management of public infrastructure. Among them, NOK will unveil its newly developed “Ammonia and Hydrogen Sulfide Detection Rubber” for the first time. The product reacts to ammonia and hydrogen sulfide and visually identifies the type of gas through changes in color.

As sewerage infrastructure continues to age, easily assessing the presence of invisible gases such as hydrogen sulfide and ammonia, which cause foul odors and pipe corrosion, has become a key challenge. Through products that make these gases visible, NOK will contribute to more efficient inspections and investigations and improved worker safety.

NOK Exhibits

● Ammonia and Hydrogen Sulfide Detection Rubber
*Product Under Development / First-Time Exhibit
This special rubber reacts to ammonia and hydrogen sulfide, making these invisible gases visible through changes in color. It turns dark blue upon contact with ammonia and black upon contact with hydrogen sulfide. No power source or maintenance is required. Simply attaching or placing the material allows users to confirm whether either gas is present and identify which gas it is.

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● Recycled Rubber Coasters Featuring Local Manhole Designs
These recycled coasters are made from rubber flash generated during the rubber product manufacturing process. Leveraging NOK’s rubber compounding and processing technologies, the waste material has been repurposed into a new product. Featuring designs inspired by local manhole covers, the coasters are intended for use as municipal merchandise and promotional giveaways.

● Hydrogen Sulfide Detection Rubber
A rubber-based detection material that changes color when exposed to hydrogen sulfide gas. Because the color change is irreversible, it enables users to confirm the history of gas occurrence. The product requires no power source or maintenance and can be easily installed by simply hanging it in place. It also offers excellent water resistance, making it suitable for use in manhole environments where water droplets may be present. Designed for surveys ranging from several hours to several weeks, it is ideal for preliminary investigations of unusual odors before conducting detailed instrument-based inspections, narrowing down the source of gas generation, and performing initial surveys across multiple locations over a wide area.

Product Page
https://products.nokgrp.com/hydrogen-sulfide-detection-rubber_basicinfo.html?wovn=en

Exhibits by Joint Exhibitor NiGK Corporation

● Hydrogen Sulfide Indicator
An indicator designed for short-term hydrogen sulfide investigations lasting approximately 10 to 30 minutes. When used in combination with NOK’s long-term Hydrogen Sulfide Detection Rubber, it enables seamless gas monitoring, from spot inspections tailored to on-site conditions to continuous monitoring.

● Oil Detection Tape
An indicator that visualizes oil leaks from equipment through a color change. It requires no power source or special tools, and installation is completed simply by applying it to the target surface. It contributes to more efficient inspection work and the prevention of equipment problems before they occur.

● Temperature Label
A temperature-detection material, including labels, that changes color when a specified temperature is reached. It requires no power source and allows users to identify temperature history easily at a glance through changes in color. It is used for temperature management in settings such as electrical equipment maintenance and manufacturing processes.

SEWAGE WORKS EXHIBITION '26 TOKYO Booth

• Organizer: Japan Sewage Works Association
• Dates: Tuesday, August 4 - Friday, August 7, 2026, 10:00-17:00
　[Opening at 10:30 on the first day / Closing at 16:00 on the final day]
• Venue: Tokyo Big Sight, West Exhibition Hall 1F (3-11-1 Ariake, Koto-ku, Tokyo)
　NOK Booth No.: AT-206
　Approximately 7 minutes on foot from Kokusai-Tenjijo Station (Rinkai Line)
　Approximately 3 minutes on foot from Tokyo Big Sight Station (Yurikamome Line)
• Official Website: https://www.gesuidouten.jp/en/
• NOK Exhibition Website: https://products.nokgrp.com/expo_sewage-works-tokyo2026.html?wovn=en