Final answer:
Division 4.3 materials will not rapidly release toxic gases upon contact with water but may produce flammable and explosive hydrogen gas. They are part of characteristic hazardous wastes that include toxic, corrosive, flammable, or reactive materials, and proper handling is vital to safety.
Step-by-step explanation:
A material classified as a Division 4.3, according to hazardous waste management guidelines, will not generate substantial quantities of toxic gases rapidly after a spill into water. These materials are known to be water-reactive and may release gases that are harmful. However, specifically for Division 4.3 substances, the key characteristic is that they will not quickly generate toxic gases upon contact with water. Instead, Division 4.3 includes substances that are dangerous when wet because they can generate flammable and potentially explosive hydrogen gas.
Hazardous wastes like those in Division 4.3, characterized by reactivity, are part of the larger category of characteristic hazardous wastes. These are materials that may be toxic, corrosive, flammable, or reactive, as defined by the US Environmental Protection Agency (US EPA). Proper disposal and handling of these wastes are crucial to minimize environmental impact and human health risks. Encouraging the design of materials that break down into benign substances and preventing pollution are part of the strategies to minimize potential accidents associated with hazardous waste.