The term ‘hazardous materials’ that many people hear about is specifically defined by Japanese law. Under the Fire Service Law in Japan, what qualifies as a hazardous material is clearly stipulated and classified based on its unique characteristics.This classification is crucial for those seeking the Type 4 Hazardous Material Handler certification, a common requirement for professionals in this field.
In this blog, we will clearly explain the basic knowledge and importance of understanding hazardous materials, particularly focusing on what is required to pass the Type 4 Hazardous Material Handler exams.
What are Hazardous Materials?
The Fire Service Law explicitly defines “hazardous materials.” Substances listed in Fire Law Schedule 1 are defined as hazardous materials, and they possess specific properties. For example, a substance may be easily oxidizable, flammable, or capable of igniting spontaneously. Based on these properties, decisions are made on how the substance should be safely handled and what precautions are necessary.
Classification of Hazardous Materials
Hazardous materials are classified based on their chemical properties as follows.
- Class 1: Oxidizing Solids – Solids that promote combustion and can easily react with other substances to cause a fire.
- Class 2: Flammable Solids – Solids that are easy to ignite and can spread flames.
- Class 3: Substances that are Spontaneously Combustible and Water-Reactive – Solids or liquids that can ignite by themselves or react dangerously with water.
- Class 4: Flammable Liquids – Liquids that can start burning at low temperatures.
- Class 5: Self-Reactive Substances – Substances that can undergo a chemical reaction without external stimulus, generating a large amount of heat or reacting explosively.
- Class 6: Oxidizing Liquids – Liquids that can oxidize other substances, potentially causing combustion or explosions.
Specific Examples of Hazardous Materials
The names of items belonging to each classification are listed in Fire Law Schedule 1.
| Class | Properties | Name |
|---|---|---|
| Class 1 | Oxidizing Solids | Chlorate Salts |
| Percarbonate Salts | ||
| Inorganic Peroxides | ||
| Hypochlorite Salts | ||
| Bromate Salts | ||
| Nitrate Salts | ||
| Iodate Salts | ||
| Permanganate Salts | ||
| Dichromate Salts | ||
| Class 2 | Flammable Solids | Phosphorus Sulfide |
| Red Phosphorus | ||
| Sulfur | ||
| Iron Powder | ||
| Metallic Powders | ||
| Magnesium | ||
| Class 3 | Spontaneously Combustible and Water-Reactive Substances | Potassium |
| Sodium | ||
| Alkylaluminum | ||
| Alkyllithium | ||
| Yellow Phosphorus | ||
| Alkali Metals | ||
| Organometallic Compounds | ||
| Metal Hydrides | ||
| Metal Phosphides | ||
| Class 4 | Flammable Liquids | Special Combustibles |
| Petroleum Class 1 | ||
| Petroleum Class 2 | ||
| Petroleum Class 3 | ||
| Petroleum Class 4 | ||
| Alcohols | ||
| Plant and Animal Oils | ||
| Class 5 | Self-Reactive Substances | Organic Peroxides |
| Nitrate Esters | ||
| Nitro Compounds | ||
| Nitroso Compounds | ||
| Azo Compounds | ||
| Diazo Compounds | ||
| Hydrazine Derivatives | ||
| Hydroxylamine | ||
| Hydroxylamine Salts | ||
| Class 6 | Oxidizing Liquids | Perchloric Acid |
| Hydrogen Peroxide | ||
| Sulfuric Acid |
Sample Exam Questions
Questions on the definition and classification of hazardous materials are posed as follows:
消防法上の危険物について、 次のうち正しいものはどれか。
(1) 第1類から第6類に分類されている。
(2) 類が増すごとに危険性は大きくなる。
(3) 常温(20°C)で固体、液体、気体である。
(4) 引火点が0°C以下の危険物は特類に分類される。
(5) 第4類危険物は、 引火性の固体、液体である。
About hazardous materials under the Fire Law, which of the following is correct?
(1) Classified from Class 1 to Class 6.
(2) The danger increases with each class.
(3) At room temperature (20°C), they exist as solid, liquid, or gas.
(4) Hazardous materials with a flash point below 0°C are classified as special.
(5) Class 4 hazardous materials are combustible solids and liquids.
法別表第１に掲げる第４類の危険物の品名に該当しないものは、次のうちどれか。
(1) 特殊引火物
(2) 第１石油類
(3) アルコール類
(4) アルキルアルミニウム
(5) 第４石油類
Which of the following does not fall under Class 4 hazardous materials as listed in Fire Law Schedule 1?
(1) Special combustibles
(2) Class 1 petroleum products
(3) Alcohol types
(4) Alkyl aluminum
(5) Class 4 petroleum products
法別表第１に掲げる第４類の危険物の品名に該当するものは、次のうちどれか。
(1) 塩素酸塩類
(2) 硫黄
(3) 黄リン
(4) ナトリウム
(5) ジエチルエーテル
Which of the following corresponds to Class 4 hazardous materials listed in Fire Law Schedule 1?
(1) Chlorate salts
(2) Sulfur
(3) Yellow phosphorus
(4) Sodium
(5) Diethyl ether
Answers and Explanation
(2) The classification of hazardous materials is based on their characteristics and is not directly related to their degree of danger.
(3) Under the Fire Law, all classified hazardous materials are either solid or liquid; gases are not included.
(4) There is no classification called ‘special’ in the Fire Law definitions.
(5) Class 4 hazardous materials are ‘flammable liquids,’ not solids.
Alkyl aluminum refers to compounds where alkyl groups are bonded to aluminum, existing as both solids and liquids. They spontaneously ignite upon contact with air, classifying them as Class 3.
They also exist as solids, therefore do not fit into the classification of Class 4 ‘flammable liquids’.
The primary assumption is that all Class 4 hazardous materials are liquids, so solids do not qualify.
(1) Chlorate salts are salts containing the chlorate ion, similar to table salt and are white crystalline solids classified as Class 1.
(2) Sulfur, a pale yellow solid, is classified as Class 2.
(3) Yellow phosphorus also a pale yellow solid, spontaneously ignites in air and thus is classified as Class 3.
(4) Sodium, being a solid metal at room temperature that reacts vigorously with water, is classified as Class 3.
(5) Diethyl ether, which vaporizes even at low temperatures and has a very low flash point, is classified as a special combustible under Class 4.
Summary
When taking the hazardous material handler’s certification exam, it is crucial to thoroughly understand these basic knowledge points. Learn how to safely handle these substances in daily life, not just for the exam but for proper real-life applications as well.
コメント