[National Qualifications You Can Aim for in Your 70s (12) - Final Installment] A Summary of the Otsu-4 Exam: Key Points to Master for Success
Over the course of 11 installments, we have learned the basic knowledge required for the Hazardous Materials Engineer Class B Group 4 exam, commonly known as "Otsu-4."
In this final installment, we will organize the content covered so far and summarize what you need to memorize and how you should study before the actual exam.
While the Otsu-4 exam requires memorizing a lot of information, the points that appear on the test are somewhat predictable.
Instead of trying to memorize everything equally, focus on ensuring you can score points on frequently tested topics.
The Otsu-4 exam consists of three subjects
The Otsu-4 exam covers the following three subjects:
Laws and regulations concerning hazardous materials... 15 questions
Basic physics and basic chemistry... 10 questions
Nature of hazardous materials and methods of fire prevention and extinguishing... 10 questions
This makes a total of 35 questions.
Also important is the passing criteria.
You must score 60% or higher in each of the three subjects.
It is not enough to get 60% or more overall.
For example, even if you get a high score in laws and regulations, you will fail if you score less than 60% in physics and chemistry.
Not neglecting your weak subjects is extremely important for Otsu-4 preparation.
Key points to grasp in laws and regulations
The laws and regulations section covers the regulation of hazardous materials based on the Fire Service Act.
Particularly important is the "designated quantity."
A representative example is:
Gasoline... 200L
Alcohols... 400L
Kerosene/Diesel oil... 1,000L
Heavy oil... 2,000L
Class 4 petroleum... 6,000L
are the amounts.
Make sure you are prepared not only for the designated quantities themselves, but also for problems that require calculating the 'multiple of the designated quantity'.
Additionally, the roles of manufacturing plants, storage facilities, and handling facilities, the duties of hazardous materials engineers, and the standards for storage and handling are also important.
Key points to remember for Physics and Chemistry
In Physics and Chemistry, the first fundamental step is to understand 'combustion'.
The three elements of combustion are
combustible material, oxygen supply source, and ignition source
respectively.
Furthermore,
flash point
ignition point
combustion range (explosion range)
complete combustion and incomplete combustion
specific gravity and vapor density
static electricity
are also items you should master.
In particular, 'flash point' and 'ignition point' are easily confused, so make sure you understand them well enough to explain the difference.
Make the properties of Class 4 hazardous materials a source of points
In the Otsu-4 exam, questions asking about the properties of Class 4 hazardous materials are important.
At the very least, you should memorize the following classifications.
Gasoline... Class 1 petroleum
Kerosene/Diesel oil... Class 2 petroleum
Heavy oil... Class 3 petroleum
Lubricating oil... Class 4 petroleum
Methanol/Ethanol... Alcohols
Furthermore, learn by combining properties such as 'whether it is water-soluble,' 'whether the vapor is heavier than air,' and 'whether the flash point is high or low.'
Rather than just memorizing the names of substances,
Classification + Designated Quantity + Properties
will make it easier to handle the questions if you learn them as a set.
Also, be sure to check the fire extinguishing methods
The three principles of fire extinguishing are
removal, suffocation, and cooling
.
For fires involving Class 4 hazardous materials, foam extinguishing agents, powder extinguishing agents, and carbon dioxide extinguishing agents are used.
You should be especially careful with water-insoluble hazardous materials like gasoline.
If you pour water directly on them, the gasoline, which is lighter than water, will spread across the surface, creating a risk of spreading the fire.
The exam will also ask questions in the format of, 'Which fire extinguishing method is suitable for this hazardous material?'
Study primarily using past exam questions
For Otsu-4 preparation, it is important not just to read the textbook repeatedly, but to solve practice problems.
Once you have learned the basics, move on to past exam questions and problem sets.
When you solve problems,
'Designated quantities are frequently asked'
'The classification of this substance appears repeatedly'
'There are many options that swap flash points and ignition points'
You will start to see patterns in the questions like these.
For questions you get wrong, do not just look at the correct answer; check why the other options are incorrect as well.
Repeating this process will improve your scoring ability.
Things to check right before the exam
When you are right before the exam, rather than expanding into new areas, review the important points you have already memorized.
In particular,
Designated quantities
Representative examples of Class 1 to Class 4 petroleum products
Differences between flash point and ignition point
The three elements of combustion
The three principles of fire extinguishing
Properties of gasoline, kerosene, and diesel fuel
The proper use of fire extinguishing agents
is something you should double-check.
Also, do not forget that you need at least 60% in all three subjects, so make sure to review your weak areas until the very end.
Jobs after obtaining the Otsu-4
In the first installment of this series, I introduced that the Otsu-4 is a qualification that can lead to jobs such as working at self-service gas stations.
While obtaining the qualification does not guarantee you will find a job, there are job openings that require an Otsu-4 holder, such as monitoring duties at self-service stations.
While the number of jobs you can apply for based on age alone may be limited, having a qualification increases the number of job openings you can apply for and that is meaningful.
Exam preparation ends when you get the qualification, but beyond that, there are ways to work that utilize it.
Concluding the series
Over the course of 12 installments, I have explained the basics of the Otsu-4 exam.
This series alone does not cover all the exam preparation you need. In the end, you must repeatedly solve problem sets and past exams to get used to the actual question format.
However, if you open a problem set from the beginning without understanding the meaning of the terms, it is difficult to make progress.
If you proceed to practice problems after understanding the basics through this series, the meaning of the question text should be much easier to understand.
The Otsu-4 is a national qualification that you can definitely pass if you study properly.
Using the knowledge you have learned so far as a foundation, please aim for success by doing plenty of practice problems.
The 'National Qualifications You Can Aim For Even in Your 70s: Otsu-4 Course' concludes with this installment.