Apparatus specifically designed to produce and apply foam is commonly found at:

The correct answer is that apparatus specifically designed to produce and apply foam is commonly found at airports. This is primarily due to the unique challenges posed by aircraft fires, which often involve flammable liquids like aviation fuel. The production and use of foam is critical in these scenarios, as foam creates a blanket over the fuel, effectively smothering the fire and preventing reignition while also cooling the heat source.

Airports typically require specialized firefighting apparatus equipped with foam systems to handle these incidents efficiently. High-capacity foam tenders and vehicles are designed to deliver large quantities of foam quickly, allowing for an effective response during critical situations.

While industrial sites and high-rise buildings may have their own fire protection measures, they do not necessitate the dedicated foam application apparatus as frequently as airports do. Municipal and volunteer fire companies might have foam capabilities, but their primary focus is not as narrowly defined as at airports, where specialized training and equipment significantly enhance firefighting efforts in aviation emergencies.