Which of the following are common incompatibility pairings?

• A. Water with air; metals with glass.
• B. Alcohols with hydrocarbons; salts with sugars.
• C. Inert gases with noble metals.
• D. Strong oxidizers with fuels; acids with bases.

Answer: (D)

Incompatibility hazards occur when two materials react violently or form dangerous byproducts when they are mixed. The pairing of a strong oxidizer with a fuel is a classic example: the oxidizer can rapidly steal electrons from the fuel, releasing a lot of heat and often leading to fire or explosion. Similarly, acids and bases—when concentrated—the neutralize each other with a large release of heat and can cause splattering or pressure buildup if confined. These are well-known dangerous combinations to avoid storing or mixing together.

The other options don’t represent common hazardous incompatibilities. Water and air don’t react in a hazardous way under normal conditions. Metals and glass don’t typically react with each other in a dangerous way. Alcohols and hydrocarbons are both organic solvents and generally compatible in terms of hazardous reactivity. Salts and sugars mix without a dangerous reaction, and inert gases with noble metals are not generally reactive pairs.