Blast from the past

Edited by the Engineeringtalk editorial team Apr 8, 2003

Michael Harris, MD of Bizerba UK, considers the likely impact of the new ATEX Directive on equipment used in potentially explosive atmospheres and argues in favour of a pre-emptive strategy.

This summer marks the end of an era.

It will see the demise of the old Explosives Atmosphere Directive, replaced by the much-talked-about ATEX Directive.

It will also bring to an end the nine-year transitional period, during which end users and manufacturers have been able voluntarily to acquaint themselves with the new legislation.

So now that it's here, what's all the fuss about.

What will the ATEX Directive actually mean.

First, it should be pointed out that there are two ATEX Directives: one relating to equipment design (ATEX 100a) and the other quantifying employers' responsibilities regarding the health and safety of personnel (ATEX 137).

Although both will have the full force of European law behind them from 1st July the remainder of this article will concentrate on Directive 94/9/EC - ATEX 100a.

The beginning of July will formerly end the testing period that started in 1994 and furnished end users with the choice of whether to follow the fledgling ATEX Directive or to continue with the archetype local, national or European requirements.

From 1st July onwards, that choice disappears and all new equipment or spare parts will have to be ATEX compliant.

Unlike most new legislation, ATEX 100a has already been adopted by some companies and is being used to illustrate the significant investments that have been made in order to produce marketable products.

For instance, under the new legislation, manufacturers are required to adopt suitable quality systems that ensure EC-type-examined products will be faithfully replicated.

In this context, manufacturers are required to have an ISO9000 quality management system in place or call on a notified body during product inspection process.

In order to help manufacturers determine which conformity assessment procedure to follow, the ATEX Directive identifies two main groups of equipment.

The first group, Categories M1/M2, comprises equipment intended for use in the underground parts of mines, while the second group addresses products intended for use in all other areas likely to become endangered by explosive atmospheres.

Each category has subdivisions that refine the selection process even further.

For instance, Group II is divided into three categories for gas (1G Zone 0, 2G Zone 1 and 3G Zone 2) also for dust (1D Zone 20, 2D Zone 21 and 3D zone 22).

The new legislation sets a number of technical and quality objectives that will encourage many manufacturers to achieve even production higher standards.

One manufacturer that has been meeting these criteria for quite some time is Bizerba, one of Europe's leading manufacturers of weighing and labelling systems.

By stealing a march on many of its competitors and incorporating stainless-steel housings, tough membrane keyboards and IP68 protection ratings, Bizerba's highly accurate systems have sported the distinctive European mark since 1996.

An example of the company's foresight is the compact ST range of weighing systems, which includes four models suitable for areas where an explosive atmosphere is expected to exist only occasionally between 10 to 1000 hours per year (Zone 1 and 21), or locales where an explosive concentration of flammable material is not expected and if released will only exist for a very short period of time up to 10 hours per year (Zone 2 and 22).

The EC guidelines on the application of equipment and protective systems intended for use in potentially explosive atmospheres state that manufacturers bear the responsibility for the "design and construction of the product in accordance with the Directive", and for "following the procedure for the assessment of the conformity of the product".

Bizerba has been meeting these objectives for over seven years and is set to continue this pathfinding role by pushing the technological boundaries and pre-empting new legislation.