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Management and Reduction of Chemical Substances

Activities and Results

Hazardous Material Management Activities

Environmentally hazardous materials are defined as materials that may be harmful to the human body or ecosystems when contained in a product. In principle, we prohibit the use of such materials in our components and raw materials. For hazardous substances that may be present as impurities, we have established tolerances and handle such materials accordingly.
With regard to the Restriction of Hazardous Substances Directive (RoHS) 1 and REACH Regulation 2 in the EU and the Administrative Measure on the Control of Pollution Caused by Electronic Information Products 3 in China, we have adopted our Green Procurement Guidelines at our production facilities in and outside of Japan and provide information necessary to meeting our customers' requirements. In addition, we submit REACH reports to the relevant authorities as required.
We stringently manage chemicals specified in the PRTR Law 4 and are working to switch to products that do not contain such substances. Our goal is to reduce our handling of these chemicals by 3% each year, and we experienced an increase, going from 33,950 kg in 2021 to 35,472 kg in 2022.

  • 1 RoHS Directive: Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations
  • 2 REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) Regulation: A regulation that requires almost all chemicals sold in the EU to be evaluated for safety and to be registered
  • 3 Administrative Measure on the Control of Pollution Caused by Electronic Information Products: A law, also called "China RoHS," that requires disclosure when certain hazardous substances are present in electronic information products and components
  • 4 PRTR Law: Law Concerning Reporting, etc. of Releases to the Environment of Specific Chemical Substances and Promoting Improvements in Their Management
PRTR Substance Amount and Air Emissions
Item Amount Air Emissions
Xylene 1,270 180
Toluene 2,399 482
Ethylbenzene 346 54
Benzene 116 28
Methylnapthalene 28,272 59
Other 3,069 169
Sum 35,472 971

Scope :
Twelve production facilities in Japan: Yamagata, Kofu, Gifu, Mie, Yamaguchi, THK NIIGATA, THK INTECHS (Sendai and Mishima), NIPPON SLIDE, and THK RHYTHM (Hamamatsu, Inasa, and Kyushu)

Efforts at Each Production Facility

THK Changzhou Plant

Changing the Cleaning Agent

In August, the Changzhou plant replaced the volatile hydrocarbon cleaning agent that was used in the return pipe ultrasonic washing machine, the washing process in unit assembly (for ball screws and small components), and the machinery assembly and component washing process with a water-soluble cleaning agent. As a result, hydrocarbon use was reduced by approximately 73 kg annually.