Designated Quantities of Class 4 Hazardous Materials

Under the Fire Service Act in Japan, strict regulations are established for the handling and storage of hazardous materials. Class 4 hazardous materials are primarily flammable liquids, posing a high risk of fire and explosion, requiring special attention in their handling. The Class 4 Hazardous Materials Handler Certification Exam (乙種第4類危険物取扱者試験) includes questions about the designated quantities of these materials, so it is crucial to thoroughly understand this topic.

About Designated Quantities

For the handling and storage of Class 4 hazardous materials, there are designated quantities stipulated by law. These quantities vary depending on the type and nature of the hazardous material, and handling amounts exceeding these limits require special equipment and notifications.

Important Points

• Except in special cases, storing or handling hazardous materials exceeding the designated quantities outside of designated facilities is prohibited. This is to prevent the increased risk of fire or explosion associated with large quantities in general areas.
• The designated quantities for gasoline, alcohols, and kerosene are particularly important and should be memorized. These substances are frequently asked about in the Class 4 Hazardous Materials Handler Certification Exam.
• Even for the same substance, the designated quantity for water-soluble liquids is twice that of non-water-soluble liquids. For example, for Class 1 petroleum products, the designated quantity for gasoline (non-water-soluble) is 200 liters, while for acetone (water-soluble) it is 400 liters. Understanding this difference and managing it appropriately is required.

Designated Quantities for Class 4 Hazardous Materials

There are designated quantities stipulated by law for the handling and storage of Class 4 hazardous materials. These quantities vary depending on the type and nature of the hazardous material. Below is a table summarizing the item names, properties, examples, and designated quantities.

Item Name	Properties	Examples	Designated Quantities
Special Inflammable Substances	－	Carbon Disulfide	50L
Class 1 Petroleum	Non-water-soluble Liquid	Gasoline	200L
	Water-soluble Liquid	Acetone	400L
Alcohols	－	Ethanol	400L
Class 2 Petroleum	Non-water-soluble Liquid	Kerosene	1,000L
	Water-soluble Liquid	1-Butanol	2,000L
Class 3 Petroleum	Non-water-soluble Liquid	Heavy Oil	2,000L
	Water-soluble Liquid	Glycerin	4,000L
Class 4 Petroleum	－	Gear Oil	6,000L
Animal and Vegetable Oils	－	Soybean Oil	10,000L

When Below Designated Quantities

• Regulations under the Fire Service Act are relaxed, but basic safety management and fire prevention measures based on local government fire prevention ordinances apply.
• Specific situations, such as transporting containerized hazardous materials by car, may still be subject to regulations under the Fire Service Act.

This ensures that appropriate safety measures and regulatory compliance are maintained, minimizing the risk of fires and accidents.

Sample Exam Question 1

Explanation
(1) Correct. The designated quantities for Class 1, Class 2, and Class 3 petroleum differ based on whether they are water-soluble or non-water-soluble.
(2) Correct. The designated quantity for water-soluble substances in Class 2 petroleum is 2000L, and for non-water-soluble substances in Class 3 petroleum, it is also 2000L.
(3) Correct. The designated quantity for water-soluble Class 1 petroleum is 400L, the same as for alcohols.
(4) Correct. The designated quantity for special inflammable substances is 50L, for Class 1 petroleum is 200L, and for alcohols is 400L; all are different.
(5) Incorrect. The designated quantity for Class 4 petroleum is 6000L, while for animal and vegetable oils, it is 10,000L; they are different.

Answer: (5)

Sample Exam Question 2