Question 823 Deck General

The correct answer is D) Dangerous when wet. According to the U.S. Department of Transportation's Hazardous Materials Regulations, a Class 4.3 substance is classified as a "Dangerous when wet" material. This means the substance emits flammable gases when in contact with water, posing a fire hazard. The other answer choices are incorrect because they do not accurately describe the Class 4.3 designation. Class A is for flammable liquids, Class B is for spontaneously combustible materials, and Class C is for flammable solids, which have different hazard characteristics compared to Class 4.3 dangerous when wet substances.