NEBOSH Practice Test

What category of equipment is permissible in Zone 0 or Zone 20?

1. Category 2 equipment

2. Category 3 equipment

3. Category 1 equipment

4. Category 4 equipment

The correct answer is: Category 1 equipment

In hazardous areas, equipment categorization is essential for ensuring safety in environments where explosive atmospheres may be present. Zone 0 and Zone 20 are classified as areas with a high likelihood of an explosive atmosphere occurring continuously or for long periods. Category 1 equipment is specifically designed for use in these highly hazardous environments. This equipment is constructed to be safe even in the event of an equipment failure, ensuring that it can operate safely in the presence of explosive gases or dust. It undergoes strict testing and is built to higher safety standards to mitigate risks. In contrast, Category 2 equipment may be used in Zone 1 or Zone 21, where explosive atmospheres are likely to occur intermittently, and Category 3 equipment is suited for areas where explosive atmospheres are unlikely to occur. Therefore, they are not suited for continuous exposure in the more hazardous Zone 0 or Zone 20. This categorization framework is crucial for maintaining safety standards in environments where hazardous materials are present, ensuring that only appropriately rated equipment is utilized to prevent ignition sources.