Explosion Protection

Generally

In the chemical, petrochemical and pharmaceutical industries, the oil and gas production, mining and many other industries, during manufacturing, processing, transportation and storage of flammable substances gases, dusts, vapors or mist may escape.

These flammable gases, vapors, mists and dusts mixed with oxygen from the air, can create an explosive atmosphere. If this atmosphere is ignited, explosions can happen and cause serious personal injury or material damage.

Employers must classify areas where hazardous explosive atmospheres may occur into zones. The classification given to a particular zone, and its size and location, depends on the likelihood of an explosive atmosphere occurring and its persistence if it does.

Areas classified into zones (0, 1, 2 for gas-vapor-mist and 20, 21, 22 for dust) must be protected from effective sources of ignition. Equipment and protective systems intended to be used in zoned areas must meet the requirements of the directive. Zone 0 and 20 require Category 1 marked equipment, zone 1 and 21 require Category 2 marked equipment and zone 2 and 22 require Category 3 marked equipment. Zone 0 and 20 are the zones with the highest risk of an explosive atmosphere being present.

The regulations apply to all equipment intended for use in explosive atmospheres, whether electrical or mechanical, including protective systems. There are two categories of equipment ‘I’ for mining and ‘II’ for surface industries. Manufacturers who apply its provisions and affix the CE marking and the Ex marking are able to sell their equipment anywhere within the European Union without any further requirements with respect to the risks covered being applied. The regulations cover a large range of equipment, potentially including equipment used on fixed offshore platforms, in petrochemical plants, mines, flour-mills and other areas where a potentially explosive atmosphere may be present.

In very broad terms, there are three preconditions for the regulations to apply: the equipment a) must have its own effective source of ignition; b) be intended for use in a potentially explosive atmosphere (air mixtures); and c) be under normal atmospheric conditions.

The regulations also covers components essential for the safe use and safety devices directly -ontributing to the safe use of the equipment in scope. These latter devices may be outside the potentially explosive environment.