May 29, 2023
Toyo Styrene Co., Ltd.

Improprieties Related to Toyo Styrene's Products
Toyo Styrene Co., Ltd. (headquarters: Minato-ku, Tokyo; President: Kenjiro Ishizuka; hereinafter“Toyo Styrene”) has identified improprieties related to certain resin products that it sells certified by
Underwriters Laboratories Limited Liability Company (“UL”), a U.S.-based independent safety
science organization (“Improprieties 1”). It has also identified improprieties related to the CMJ
Registration System, a components and materials registration system established under the ElectricalAppliances and Materials Safety Act of Japan (“Improprieties 2”). The details of these improprieties
are described below.
Toyo Styrene deeply apologizes to customers and all those concerned for the considerable
inconvenience this matter has caused.
Toyo Styrene has reported Improprieties 1 to UL Japan, Inc. and reported Improprieties 2 to Japan
Electrical Safety & Environment Technology Laboratories (“JET”) and will explain the Improprieties
to those concerned individually. In addition to this, Toyo Styrene will naturally correct theImproprieties and take determined steps to improve quality assurance for its products.
Responding to the identified Improprieties, Denka Company Limited, which is Toyo Styrene's largest
shareholder, decided on May 29, 2023, to establish an external investigation committee consisting ofoutside experts. Toyo Styrene will fully cooperate with the external investigation committee'sinvestigation and will thoroughly investigate the Improprieties, determine their causes, and formulate
measures to prevent any recurrence.
Toyo Styrene has always believed in the importance of compliance. Having identified theImproprieties, the company will strengthen compliance and work to prevent any recurrence. Toyo
Styrene is committed to restoring the trust of all concerned.
1. Overview of improprieties(1) Improprieties 1(i) Description• Toyo Styrene changed the composition of certain products from the registered composition which
affected the resin flammability grade according to the UL 94 standard. Toyo Styrene manufactured
and sold these products without filing the changes with UL.
• Toyo Styrene created pieces of resin from materials including more flame retardants than the resinin the designated lot for follow-up flammability testing conducted by UL and provided them to UL.
(ii) Products found not to be compliant
All product types (15 types) of Toyo Styrene Flame Retardant PS, which is certified by UL(Grades: LX20, NR120C, LH20, F2C, LH30, FX2C, LF21, FP120C, F2, J2, EJ2C, NBW1601,
FS100S, ES150, J5)

An internal investigation of Toyo Styrene has revealed that J5 does not meet the flammability
standard.
(iii) Date improprieties occurred
Similar improprieties were disclosed by another company last year, and Toyo Styrene conducted aninternal investigation to see if it has any similar problems. Toyo Styrene identified the Improprieties
1 in October 2022.
(2) Improprieties 2(i) Description
To check that electrical appliances (such as air conditioners and refrigerators) meet the technicalstandards set forth in the Electrical Appliances and Materials Safety Act, the components andmaterials that the appliances are composed of must be tested.
Manufacturers can streamline testing by using components and materials registered in a registration
system for components and materials used in electrical products (CMJ Registration System).
Certain products of Toyo Styrene are registered in the CMJ Registration System. It was found in
2019 that Toyo Styrene provided samples that were not from the lots specified by JET, theregistration authority, for the ball pressure testing (tests checking the heat resistance temperature ofmaterials used for electrical appliances) conducted by JET.
(ii) Product found to be non-conforming
A Toyo Styrene Flame Retardant product (grade: NBW1601)(iii) Date improprieties occurred
After the discovery of Improprieties 1, Toyo Styrene checked if it had any other problems. In midMay 2023, Toyo Styrene identified Improprieties 2.
2. Impact on final products
Toyo Styrene has not received any reports about accidents, etc. related to final products using theToyo Styrene products involved in the Improprieties. Nevertheless, Toyo Styrene will continue toexamine the safety and performance of the final products in cooperation with customers.
[For Inquiries about This Press Release from Media]
Administration Division Tel: +81-3-3519-5600[Contact for Inquiries from customers]
Sales Division Tel:(Tokyo) +81-3-3519-5602 and (Osaka) +81-6-6221-4500