Hazardous Information

The ATEX directive defines the mandatory requirements for manufacturers and users of all hazardous area equipment sold in the European Union. Each must have applicable ATEX certificates. Other countries accept the IECEx standard, which is derived from similar principles.

In addition to the technical requirements demanded by the appropriate standards for each type of protection concept, the Atex Directive imposes additional requirements on the certificate holder in terms of quality system, product documentation, installation information, possible limitations of use in the relation to its intended environment, labelling information etc.

Equipment Marking

Marking of equipment shall include the following typical data:

Ex II 2 G, Ex II 3 D

Where II is the equipment group; 2 is the category for use (see table for equivalent zone); G (or D) is the type of explosive atmosphere - G = gas, vapour or mist; and D = Dust

IIC T4 Ta = -20°C to + SS°C

IIC refers to the gas group, and where the T class will vary against ambient

IIC TS Ta = -20°C to + 2S°C

The T class marking for dust may also be shown if different to gas

As manufacturers we design and construct our products in such a way so that they will not provide a source of ignition, each type of protection achieves its safety from ignition in a different way. It is essential that those who specify and or select products, ensure that they are suitable for the ZONE in which they are to be installed and are appropriate for the Gas Groups and the Temperature Class required by referencing BS EN 60079-14. All equipment installed in hazardous areas is inspected and maintained at regular intervals so as to ensure the continued integrity of the protection concepts used on the equipment design. Such inspections and maintenance should be carried out in accordance with BS EN 60079-17 and, where applicable, the manufacturer's instructions. Specific records should be kept on site locally of all maintenance carried our on such equipment. these shall allow the unique identification of each item of equipment system.

Categories and Zone definitions for gas and dust

Dust

Zone 20 - A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently.

Zone 21 -  A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally.

Zone 22 -  A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only.

Gas

Zone 0 - A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is present continuously or for long periods or frequently.

Zone 1 -  A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.

Zone 2 -  A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.

Working in explosive atmospheres

Personnel who work in an explosive atmosphere must understand the risk and the dangers and they must be competent. If personnel are not competent the potential for accidents in hazardous areas is significantly increased. There are many legal requirements for competence however this is not always clearly understood by employers. Competence can be described as the combination of training, skills, experience and knowledge that a person has and their ability to apply them to perform a task safely.

Competency and Training

The specification, selection, installation, maintenance, removal for repair and replacement of apparatus, system and installations should be carried out only be personnel whose training has included instruction on the various types of protection and installation practices and where appropriate the principles of area classification i.e. CompEx Training and Assessment.

Standards

The following standard should be consulted when carrying out specification, selection, installation, inspection, maintenance and repair of electrical equipment.

BS EN 60079-17 Inspection and maintenance of electrical installations in hazardous areas (other than mines).

BS EN60079-14 Electrical installations in hazardous areas (other than mines).

BS IEC 600079-19 Repair and overhaul for apparatus used in explosive atmospheres (other than mines or explosives).