Which of the following substances would be classified as hazardous?

The classification of a substance as hazardous often depends on its chemical properties and potential health or safety risks. Substances that are explosive or flammable pose significant dangers in various settings, including workplaces and residential areas. These types of substances can lead to fires, explosions, and serious injuries if not handled properly.

By being classified as hazardous, explosive or flammable substances require specific safety measures such as proper storage, labeling, and training for individuals who might handle them. Proper understanding of these characteristics is vital in occupational safety and health, particularly in the construction industry, where handling various substances is commonplace and safety regulations must be adhered to.

In contrast, substances that are chemically inert do not react or pose immediate risks under standard conditions, and while common household substances may have some risks, they do not inherently classify as hazardous just by being present in a household. Regular cleaning substances may also have varying levels of hazards but are generally not classified as hazardous unless specifically identified as such when they contain dangerous chemicals. Thus, the most clear and direct classification of a hazardous substance from the options provided is someone that is explosive or flammable due to the significant risks they present.