The Importance of Hazardous Area Classifications in ATEX Fan Selection
In many of the industries our customers operate in, there are explosive or dangerous hazards present, whether continuously, occasionally, or rarely. Hazards such as leakage of flammable gases, dangers of gases accumulating in confined spaces, release of toxic gases, or exposure to aggressive chemicals are just a few examples that can be considered risky hazardous situations with a potential to cause an explosion.
To ensure safety in these dangerous applications, there are several directives and regulations that offer guidance – most importantly ATEX and DSEAR regulations. In areas that are considered as potentially explosive, end users need to undertake an explosion risk assessment, and hazardous area classification to determine the accurate ATEX classification and zone. They need to ensure, not only that the equipment meets the safety standard for the zone in which it is used, but also provide suitable warning signs with adequate documentation such as an Explosion Protection Document (EPD). DSEAR bodies can be contracted to undertake an audit to ensure compliance.
What are Dangerous Substances?
Dangerous substances refer to any substances present at work that could, if not properly controlled, cause harm to people as a result of a fire, explosion or corrosion of metal. They can be found in nearly all workplaces and include such things as solvents, paints, varnishes, flammable gases, dusts from machining and sanding operations, dusts from foods, pressurised gases and substances corrosive to metal.
Do I Need An Assessment?
Whether your work activities create, control or release flammable gases or vapours, such as vehicle paint spraying, exhausting toxic fumes from production activities, or you handle fine organic dusts such as grain flour or wood, a DSEAR audit will ensure you meet the relevant legislation for your industry and reduce the risk of serious injury or explosions. In short if you think there is a risk of explosion with any of the substances or activities being undertaken, a hazardous areas classification can ensure you stay on the right side of safe, protecting systems, processes, buildings, and employees from harm.
There are lots of companies in the UK that can be contracted to complete a risk assessment and compile a hazardous area document tat can be used to source equipment for potentially explosive environments. Important Information In line with the ATEX Directive it is strictly the responsibility of the end user to undertake a DSEAR risk assessment to ensure that ATEX classifications are properly defined in terms recognised by ATEX 99/92/EC. Please contact SGS on 0151 350 660 or visit www.sgs.co.uk to book an assessment.
Most explosion risk assessments will include the below processes:
• Initial consultation to assess your requirements and plan the assessment.
• Identify the directives and standards which apply. For example, ATEX Directive 2014/34/EU is the ATEX equipment directive that places legal requirements on suppliers of equipment and protective systems for use in potentially explosive atmospheres. This is one that your equipment manufacturer will follow closely to ensure that components are manufactured in a construction material that prevents friction and sparks from non-permissible materials coming into contact with one another, or by ensuring motors are intrinsically safe to contain any explosion within the enclosure body itself, again preventing ignition from sparks. The list is quite extensive that must be followed to determine the suitability of product for hazardous areas.
• Identify and record the substances that present an explosion hazard and their properties. It is important to consider the properties of individual gases and dusts to determine the potential for explosions under different circumstances. For example, the auto ignition temperature of a potentially flammable gas is an important thing to consider. If temperatures reach or exceed this temperature, the temperature of the gas will raise and ignite spontaneously with the absence of a spark or flame. For example, gasoline has an auto ignition temperature of 280 degrees. Another assessment is the minimum ignition energy of the gas or dust, this is a measure of how sensitive an explosive substance is to electrical spark ignition, mechanical ignition, or electromagnetic radiation. The lower the figure, the higher the risk of explosion as a very small energy input can trigger an explosion. Hydrogen has a low MIE of 0.011, meaning it is a very risky, dangerous gas and should be dealt with caution in explosive environments. It’s an important parameter for the design of protective measures when selecting equipment for ATEX zones.
• Complete an explosion hazard “area classification” that will list “sources of release” where hazardous substances may be released from equipment deliberately or accidentally, and define the “zones” where they may mix with air and form an explosive atmosphere. Zones 0, 1 and 2 relate to flammable gas environments, while zones 20, 21 and 22 relate to combustible dust environments. Learn more about ATEX gas and dust zones here.
• Complete an “Ignition Risk Assessment” which will identify and analyse the ignition hazards such as sparks and hot parts that could ignite the explosive atmospheres. They will also assess whether the measures in place to prevent ignition conform to ATEX standards. Equipment zones will be identified. There are many sources of ignition including mechanical friction sparks, electrical sparks, thermal ignition, and auto ignition initiated by high temperatures. Learn more about ATEX motor classifications to determine the different levels of explosion protection offered, such as Ex be, Ex ec, Ex Na etc.
• Putting information on substances, sources of release, zones and ignition hazards in the format required by the international standards.
• Provide help with the ATEX Equipment Directive’s requirements for Notified Bodies, certificates, quality systems and Declarations of Conformity. With the UK leaving the European Union, ATEX has been adopted into UK statutory legislation. The plan is that the term UKEX will eventually supersede ATEX in the UK, ensuring that all equipment placed on the UK market will be certified under the new directive, with certificates that show compliance with UKCA and UKEX laws. Learn more about UKEX here.
• Provide help with the ATEX Worker Directive’s requirements for markings and signs, PPE, instructions, emergency procedures, training and competence, inspections and other organisational measures.
• Help to compile a technical file or explosion protection document with the information required by the directives. Fan manufacturers and authorised bodies will always supply you with a copy of the certificate and the datasheet to occupy the fan and motor component. You’re advised to check over the documentation before completing your purchase to ensure that the product selected is in line with the specified hazardous area classification you issued to the supplier.
• Provide you a report outlining areas of non-compliance and advice to help you rectify them.
ATEX Fan Selection
When selecting a fan for your ATEX application, we’ll aways ask for some of the information from your hazardous area assessment. This will include the gas or dust zone (zone 1 , 2 etc), the Temperature Class (T Class T1, T2 etc), the gas group (IIC, IIB, IIA) and the gases present. This will allow us to determine the safest fan and motor combination including construction materials, motor classification, the maximum surface temperature, and the explosion protection characteristics. Legislation states that this information must come from the end user so therefore if our customers do not have this information readily available to send to us in a written format, we will decline to quote. This ensures safety for us, and you that may happen with selections that are based on assumptions. For more information contact us on [email protected] or start a chat with one of our technical team on the bottom of this page.
