NEBOSH Practice Test

The correct answer is based on the principle that using explosion-proof certified equipment is essential in environments where flammable materials, such as radioactive sludge, are present. Such equipment is specifically designed to prevent explosions and fires by containing any potential ignition sources. This is particularly important when handling materials that can pose both radiation hazards and fire risks.

In environments where radioactive substances are present, it is crucial to use tools and equipment that are capable of withstanding the dangerous conditions that might arise. Standards for explosion-proof equipment ensure that any sparks or thermal effects that might result from equipment malfunctions do not lead to ignition of flammable materials, thus significantly reducing the risk of fire.

Considering the other options, increased ventilation might help dissipate heat or fumes but does not directly address the risk of ignition from mechanical equipment. Working without PPE is generally unsafe and increases risks to personnel rather than mitigating those risks. Frequent relocation of sludge might reduce exposure but does not specifically address fire risks associated with equipment used in handling the sludge. Therefore, using explosion-proof certified equipment is the most effective control measure in this context.