Name an example of incompatible classes that must be segregated.

• A. Water with acids.
• B. Acids and alkalis; oxidizers and fuels; explosives with flammable materials.
• C. Non-hazardous materials with flammable liquids.
• D. Inert gases with oxidizers.

Answer: (B)

In dangerous goods packing and shipping, some class combinations are so chemically incompatible that they must be kept apart to prevent dangerous reactions, fires, or explosions. An example that clearly shows this is acids and alkalis, oxidizers and fuels, and explosives with flammable materials. Acid and alkali contact can produce violent neutralization, releasing heat and potentially irritating fumes. Oxidizers can supply the oxygen that fuels copious, rapid burning, so when they meet fuels the risk of a severe fire or explosion rises dramatically. Explosives paired with flammable materials is an especially dangerous mix because the presence of a flammable substance can trigger or amplify an explosive event.

Other options don’t illustrate the segregation concept as strongly. Water with acids isn’t the typical pairing highlighted for incompatibility in packing rules, since adding water to acids is a well-known procedure rather than a unique incompatibility. Non-hazardous materials with flammable liquids may be permitted under certain conditions and don’t represent the classic, high-risk incompatibility. Inert gases with oxidizers can present hazards in some contexts, but the most straightforward and widely emphasized incompatibilities involve acid–alkali, oxidizer–fuel, and explosives–flammables.