Which statement about decomposition products is true?

• A. They always present different hazards
• B. They always present the same hazards
• C. They are never hazardous
• D. They are often present different hazards than the original

Answer: (D)

When a chemical decomposes, the substances formed can have very different properties from the starting material, so the hazards you face can change. The hazard profile depends on what the decomposition products are and their behavior—things like toxicity, flammability, and corrosivity. Because decomposition often produces gases or reactive species that weren’t present in the original material, it’s common for the hazards to change in magnitude or type. That’s why the statement that decomposition products are often present with different hazards than the original is the best fit.

It isn’t a universal rule that they always differ—sometimes the hazard characteristics may be similar or the risk may be driven by other factors—but in practice, decomposition frequently introduces new or different hazards to manage.