What is the increased risk associated with 25% oxygen?

The correct answer is the increased fire risk associated with 25% oxygen levels. Oxygen is a key component in the fire triangle, which includes heat and fuel. At higher concentrations of oxygen, such as 25%, materials that are typically considered non-flammable can ignite more easily and burn more vigorously. This is because the presence of excess oxygen supports combustion, allowing fires to start more readily and spread faster.

In normal atmospheric conditions, which consist of approximately 21% oxygen, many materials require an initial source of ignition to catch fire. However, when oxygen levels are elevated, even the smallest spark or heat source can lead to combustion. This is particularly critical in environments where flammable materials are present.

Given the context of collection systems and maintenance practices, understanding the implications of oxygen levels is vital for safety protocols and operational procedures. The other options, such as asphyxiation risk, brain damage, and corrosion of materials, may relate to different hazards associated with varying environments but do not directly result from the inhalation of elevated oxygen levels in the same way that increased fire risk does.