"乙種4類危険物取扱者試験 令和5年版" (Class 4 Hazardous Materials Handler Examination, 2023 Edition) Koron Publishing Price: ¥1636 Using only this book, I was able to score 80% on laws, 100% on physics/chemistry, and 80% on properties/extinguishment on the 2024 exam. (Perhaps being a science student helped?) Stars are marked according to the frequency of questions, so it's easy to understand where to focus your studies. No writing inside. #KoronPublishing #Book #Engineering/Industry/Other