危険物乙4 一問一答

Prepare for Japan's 危険物取扱者 乙種第4類 (Class 4 Hazardous Materials Handler)
qualification with 1,037 practice questions, detailed explanations and a full mock
examination - all working completely offline.

WHY THIS APP
- 1,037 practice questions covering the entire Class 4 syllabus, organized into 19 topics.
- A full explanation for every question, not just the correct answer.
- Exam Mode reproduces the real exam: 35 questions, 120 minutes, pass or fail per subject.
- 100% offline. No account, no sign-up, no advertisements, no tracking.
- Japanese and English interface.

FULL SUBJECT COVERAGE
- Laws and regulations on hazardous materials (危険物に関する法令) - 441 questions
- Basic physics and chemistry (基礎的な物理学及び基礎的な化学) - 298 questions
- Properties, fire prevention and extinguishing (性質及び火災予防・消火の方法) - 298 questions

All 19 topics of the syllabus are covered: definitions and classification, designated
quantities, facility types, structure and technical standards, prevention rules and safety
supervisors, handler licenses, signs and displays, combustion, flash point and ignition
point, vapour and vapour pressure, static electricity, heat transfer, density and specific
gravity, chemical reactions, common properties of Class 4 materials, water solubility and
extinguishing methods, extinguishing agents, substance properties, and storage safety.

MODES
Quick Q&A (一問一答)
Answer one question at a time with immediate feedback, and reveal the explanation whenever
you want it. Ideal for short sessions and for working through a topic from start to finish.

Exam Mode (本番モード)
A mock examination built to match the real one: 35 questions distributed 15 / 10 / 10 across
the three subjects, a 120-minute countdown, and the official pass criterion of 60% or more
in every subject. A per-subject breakdown shows exactly which subject is holding you back.

Mistake Notes (間違いノート)
Every question you answer incorrectly is collected automatically, so you can redo only your
weak questions instead of grinding through material you already know.

Statistics (学習統計)
Total questions answered and correct, overall accuracy, your consecutive study-day streak,
accuracy by subject, and recent activity.

Memorize Data (暗記データ)
Quick-reference tables for the figures that are easiest to confuse: designated quantities,
classification by flash point, and the properties of typical hazardous substances.

EXPLANATIONS THAT ACTUALLY TEACH
Each question includes the reason the correct answer is correct, why each of the other
options fails, the legal or scientific basis, a memory hook, and how often the topic
appears on the exam.

PRACTICE THE WAY YOU WANT
Filter by subject, topic, year, or number of questions, or restrict a session to questions
you have previously missed. Build a 10-question warm-up or work through a whole subject in
one sitting.

Your progress, accuracy and study streak are saved on your device, so you can close the app
and pick up exactly where you left off. Nothing is uploaded - the app never goes online.

WHO IT IS FOR
- First-time candidates for the Class 4 Hazardous Materials Handler examination
- Anyone retaking the exam who wants targeted revision
- Gas station, tank truck, chemical plant, paint and solvent industry staff who need the
qualification for work

IMPORTANT NOTES
- An independent study aid, not affiliated with, endorsed by or connected to the Japanese
Fire and Disaster Management Agency (消防庁) or any official examination body.
- Reference values are for exam preparation; always confirm official figures against the
applicable laws and official materials.
- No advertisements and no in-app purchases.

Privacy: no personal data collected, no account required, fully offline.