What are the hazardous flammable solids in Subject 4?

[SanJason]

Hazardous flammable solids in Subject 4 include matches, etc. Below is an introduction to the knowledge related to the driver's license test: 1. Definition of driver's license: The full name of the driver's license is the motor vehicle driver's license, which is the certificate required by law for motor vehicle drivers. 2. Definition of Subject 1 test: Subject 1, also known as the Subject 1 theory test or driver theory test, is part of the motor vehicle driver's license assessment. According to the "Regulations on the Application and Use of Motor Vehicle Driver's Licenses," the test content includes driving theory basics, road safety laws and regulations, local regulations, and other related knowledge. The test format is computer-based, with 100 questions, and a passing score of 90 or above.

[CarterRose]

I remember memorizing the part about flammable solids when preparing for the Subject 4 exam. The most frequently tested items include matches, sulfur, and red phosphorus, especially red phosphorus which is prone to spontaneous combustion—remember its difference from ordinary red phosphorus. Also, magnesium powder is dangerous; there was news about how difficult it was to extinguish a magnesium powder fire in a factory. Nitrocellulose requires special attention—it's used as bullet primer material, and this point is often tested. Others like activated carbon and aluminum powder also frequently appear on the list. When driving, if you encounter trucks carrying these hazardous materials, remember to keep a safe distance and avoid keeping matches in the car. For review, I recommend focusing on memorizing their flammable properties—this is more useful than just memorizing the names.

[CollinLee]

We veteran long-haul drivers are well aware that hazardous materials are categorized into several classes. The flammable solids section is covered in detail in the Category 4 exam, mainly including matches, sulfur, and red phosphorus. Everyone is familiar with matches, but don't assume sulfur is only encountered at hot springs—it releases toxic gases when heated. Red phosphorus requires even more caution as it can ignite from friction, so extra care is needed during loading. Our company regulations require such cargo to be packed separately in well-ventilated compartments with dry powder fire extinguishers on standby. Exam questions often ask how to handle these materials, but the key is simply following safety protocols—avoiding high temperatures and sparks is crucial.

[McFrancisco]

Those who have worked in chemical plants are well aware of the properties of hazardous solids. The flammable solids tested in Subject 4, such as sulfur, may appear as yellow rocks under normal conditions but can burn violently when reaching their ignition point. Red phosphorus is even more dangerous, as slight heating or friction can trigger a fire. Magnesium powder is not only flammable but also reacts violently with water. When driving, if you encounter a truck labeled with such hazardous materials, keeping a safe distance is the best strategy. At home, be cautious not to store matches with other flammable materials. Remembering these characteristics is far more useful than memorizing names.

[Dominic]

When reviewing for Subject 4, I compiled a list of hazardous materials. Flammable solids mainly include matches, sulfur, red phosphorus, magnesium powder, and nitrocellulose. Among these, matches and sulfur are more common, while red phosphorus can ignite upon impact, making it highly dangerous. The exam often tests the differences in characteristics of various solids, such as activated charcoal, which is also a flammable solid but has a higher ignition point. There are also differences in transportation regulations; sulfur can be transported by ordinary trucks, but nitrocellulose requires specialized explosion-proof vehicles. These points can be easily memorized by summarizing them while practicing the question bank.