In most countries, there are legal or other similar regulations for potentially explosive atmospheres that can harm people, plant, machinery or the environment. The International Electrotechnical Commission (IEC) is responsible for global standards in the area of electrotechnology.

IEC publications, which define the explosion protection for electrical equipment and systems, are prepared by the Technical Committee TC31 that are equated to recommendations. The regulations for potentially explosive gas atmospheres and combustible dust are set out in the IEC 60079 series of standards. National specifications may, however, deviate from these standards. For this reason, the extent to which the IEC standards can be applied in the individual countries must be checked.

International Organization for Standardization (ISO) has published standards for non-electrical equipment:

• ISO 80079-36: Non-electrical equipment for explosive atmospheres - Basic method and requirements
• ISO 80079-37: Non-electrical equipment for explosive atmospheres - Non-electrical type of protection constructional safety "c", control of ignition sources "b", liquid immersion "k"
• ISO 80079-38: Equipment and components in explosive atmospheres in underground mines

The laws of physics and chemistry relating to the development of explosions are valid worldwide, with some minor deviations. It is therefore worth subjecting the approval conditions for electrical equipment to a global regulation and allowing the free international movement of goods by means of non-country or non-region-specific certificates. The IEC has designed a procedure with this standardisation in mind – the IECEx scheme.

The IECEx scheme currently comprises of three components for the international testing and certification of the following:

1. Equipment used for explosion protection

2. Services, maintenance and repair of explosion-protected equipment

3. Skills of the people working in potentially explosive atmospheres

Our "Essential Explosion Protection" brochure contains further information about the relevant applicable statutory mandates and standards in explosion protection, on zone classifications and types of protection, on physical and technical bases and on operating and maintenance of systems in potentially explosive atmospheres.

Statutory mandates and standards relating to explosion protection first existed at national level. Later on, these were replaced by European directives and standards. ATEX Directive 2014/34/EU (manufacturers) and Directive 1999/92/EC (plant operators) with risk assessment as the key element are thus also decisive for Germany.

This directive sets out the requirements for the quality of explosion-protected equipment and protection systems (e.g. by determining the construction type, certification, manufacturing and quality assurance, marking, operating instructions and the declaration of conformity), wherein the important health and safety requirements are specified that are to be complied with by the manufacturer and/or the importer.

These "Minimum requirements for improving the health and safety protection of the worker at risk from explosive atmospheres" refer to the operation of potentially explosive plants, and is therefore intended for the operator (employer).

In accordance with this Directive 1999/92/EC, the operator must assess the explosion hazard of the plant, classify the plant into hazard zones, and document all measures for the protection of workers in the explosion protection document.

*(official versions available in German only)

In North America, explosion protection for electrical equipment and systems vary slightly from the IEC technology. The differences can be found, for example, in the classification of potentially explosive atmospheres, the equipment design and the installation of electrical systems.

The National Electrical Code (NEC) in the USA and the Canadian Electrical Code (CEC) in Canada apply to electrical equipment and systems used in potentially explosive operating facilities. These are similar to installation regulations for electrical systems in all areas and refer to a range of other standards of other institutions which contain regulations for the installation and construction of suitable equipment.

In the USA, these are mainly the standards issued by Underwriters Laboratories Inc. (UL) and the International Society of Automation (ISA). In Canada, it is the Canadian Standards Association (CSA).