Lighting plays a vital role in a safe, efficient and productive industrial facility or production process plant. During the night, facilities with enclosed areas and 24-hour work operations rely on them exclusively for illumination.
However, facilities for industries such as petrochemical, refining, and grain storage, require more from their lighting. In addition to providing light, lighting units for these industries must address and overcome the inherent challenges of hazardous environments. The Hazardous environment lighting units are designed to specifically handle the highly corrosive elements, combustible dusts and flammable gases and vapours that are endemic to these industries.
An explosive atmosphere in this case is a mix of air and flammable substances in the form of fumes, mist or dust. Any ignition source can cause combustion that propagates through the atmosphere leading to an explosion and flames that spread rapidly. Various regulations are in place which stipulate special precautions to protect worker health and safety and avoid the risks inherent in explosive atmospheres.
Hazardous Location Lighting
Lighting for hazardous locations are often termed as ‘HazLoc’ lights which are designed to minimise the risk of explosions caused by any sparks within its housing or any other accidental events. Such lights are explosion-proof and are meant to ensure overall well-being of not just workers, but businesses as well. When you add Light Emitting Diodes (LEDs) to the mix, it further ensures that you save on energy costs without compromising on safety. HazLoc LEDs are put through rigorous tests and safety procedures, go through stringent quality checks, and are certified before being sold for use.
LED Industry Standards
NFPA: The National Fire Protection Association (NFPA) is a global non-profit organisation that publishes information about different codes and standards that are relevant to various industries and their practices. It also delivers information and knowledge on hazard assessment via NFPA 497 (explosive gas) and NFPA 499 (dust). The NFPA 70® is for the National Electrical Code (NEC).
NEC: The National Electrical Code (NEC) under NFPA 70® is “the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards”. It covers electrical installations/removal, electrical conductors, equipment, and raceways, among others, in locations like public and private premises, industrial substations, etc.
“lighting designed to handle highly corrosive elements, combustible dusts and flammable gases”
IP Rating: Ingress Protection or International Protection (IP) rating is a set of codes implemented to rate and classify the degree of protection provided by mechanical casings and electrical enclosures against different elements. Some of these elements include dust and water, intrusion, accidental contact, etc.
Impact Protection (IK) Rating: Impact protection rating, according to UL, is defined “as IKXX, where “XX” is a number from 00 to 10 indicating the degrees of protection provided by electrical enclosures (including lighting units) against external mechanical impacts”. It determines the ability of electrical or lighting enclosures to withstand high energy impacts, how it should be mounted, atmospheric conditions, among other criteria.
NEMA: The National Electrical Manufacturers Association (NEMA) defines different heavy-duty electrical enclosures for various categories of lighting depending on access to hazardous parts and additional type-dependent designated environmental conditions. Such LED products are usually seen in industrial as well as hazardous locations.
ATEX: The Atmosphères Explosibles (ATEX) is a certification standard by the European Union that “covers equipment and protective systems intended for use in potentially explosive atmospheres”. According to UL, HazLoc and explosion-proof equipment that are ‘intended for installation’ in the EU region should be compliant with ATEX Directive 2014/34/EU.
IECEx: The International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres (IECEx System) is meant to “facilitate international trade in equipment and services for use in explosive atmospheres, while maintaining the required level of safety”. It defines ‘Ex’ areas as “Hazardous Locations”, “Hazardous Areas”, or “Explosive Atmospheres”.
RoHS: The Restriction of Hazardous Substances Directive (RoHS) restricts the use of certain hazardous substances in electrical and electronic equipment. HazLoc LED products with RoHS certification assure not just quality but sustainable practices as well.
The Benefits of LEDs
There are several advantages of using LEDs designed specifically for hazardous locations.
Standard light fixtures are usually composed of a design that exposes the bulb, contacts, wiring, and switches to external atmosphere. In such cases, a spark from a loose contact, movement of the switch, or even heat from the bulb is enough to ignite in a flammable environment. However, in case of explosion-proof LED lights, the components are encased to prevent potential sparks or flames from escaping the internal housing.
Explosion-proof LED lights are built with a sturdy frame and thicker tempered glass lenses, making them highly resistant to vibrations. This durable design allows the easy transportation of these lights from one place to another by forklifts or other machines without the risk of damage or malfunction, thus making them more portable. This feature also makes them an ideal choice for operators who require mobile illumination.
“HazLoc LED lights put to use more than 90 per cent of the energy to produce light and have near-zero heat or conversion loss”
Given the rugged build of the explosion-proof light fixtures with sturdier materials, they offer a high degree of durability in comparison to standard light fixtures as they can withstand harsher working environments. This makes them a better choice for operators as it will not be easily damaged like standard light fixtures, and would reduce maintenance and furbishing costs.
Explosion-proof HazLoc LED lights are also extremely energy efficient. They put to use more than 90 per cent of the energy to produce light and have near-zero heat or conversion loss to account for, which means that they use a lot less power to function. Additionally, organisations save on-site energy from portable generators and other in situ sources, providing more sustainable and profitable operations. In other words, you can save more money from explosion-proof LEDs in comparison to standard non-LED explosion-proof lighting units.
Modern explosion-proof LED lights come in modular designs and multiple mounting options to allow multitudes of options in their application. They allow light output to be easily adjusted to match your required light levels or adapt to existing access points, all while saving energy and money.
Apart from the above-mentioned benefits, another aspect that sets HazLoc LEDs apart from other HazLoc lighting is that the former is mercury-free and environment-friendly. It reduces disposal costs and is a sustainable alternative to your lighting requirements.
What is ATEX?
ATEX is derived from the term “ATmosphere EXplosibles” and it is a mandatory certification for all products to be sold across Europe. ATEX consists of two European Directives that mandate the type of equipment and work conditions allowed in a hazardous environment.
ATEX 95 Directive
The ATEX 2014/34/EC Directive, also known as ATEX 95, applies to the manufacture of all equipment and products that are used in potentially explosive environments. The ATEX 95 Directive states the basic health and safety requirements that all explosion proof equipment and safety products have to meet in order to be traded in Europe.
ATEX 137 Directive
The ATEX 99/92/EC Directive, also known as ATEX 137, is aimed at protecting the health and safety of employees who are constantly exposed to potentially explosive working environments. The directive states:
- Basic requirements to protect the safety and health of workers
- Classification of areas that may contain a potentially explosive atmosphere
- Areas that contain a potentially explosive atmosphere have to be accompanied with a warning symbol
What is IECEx?
IECEx stands for the certification by the International Electrotechnical Commission for Explosive Atmospheres.
To be IECEx certified, all products must go through a monitored process by the International Electrotechnical Commission to ensure that they meet the minimum safety requirements. This process will determine if the products can be used in hazardous or potentially explosive locations.
“IECEx certification allows products to be traded across countries without having to be re-tested for every country”
Being IECEx certified allows the products and equipment to be traded across countries without having to be re-tested and re-certified for every country. As different countries adhere to different safety standards, products from one country have to be re-tested in another country to abide by its guidelines for use in hazardous areas. Therefore, IECEx acts as a common set of safety standards amongst participating countries certification which helps to reduce testing and certification costs for manufacturers. Participating countries in the IECEx Scheme include the majority of countries in Europe, Canada, Australia, Russia, China, United States and South Africa.
Key Differences Between ATEX and IECEx
The main difference between ATEX and IECEx is that ATEX certification only applies for countries in the EU while IECEx certification is accepted globally. Hence, the IECEx certification is more widely recognised and accepted compared to ATEX certification.
Another key difference between ATEX and IECEx certifications is that ATEX is law-driven while IECEx is standard-driven. The manufacturer is accountable for the entire ATEX certification process for products. On the other hand, the responsibility lies with the external certification party to ensure that the necessary products are IECEx certified. One fundamental way that ATEX differs from IECEx is the way each certification is set up. The IECEx certification consists of four schemes: IECEx Equipment Scheme, IECEx Conformity Mark License, IECEx Services Scheme, and IECEx Certified Persons Scheme. These four schemes are to ensure that every aspect of the products conforms to the IECEx standard, from the quality of the Ex-equipment itself to the competency of the personnel who will be handling such equipment in hazardous environments. On the other hand, the ATEX certification only consists of two directives: ATEX 95 and ATEX 137.
“difference between ATEX and IECEx certifications is that ATEX is law-driven while IECEx is standard-driven”
Furthermore, ATEX certification can be based on an IECEx test report, but an ATEX documentation may not necessarily support an IECEx certificate. Therefore, it has become a common industry requirement for products to contain both ATEX and IECEx certificates.
Selecting ATEX Lighting
For prior planning, procurement consideration and selection of lighting in ATEX, we need to focus on initial information on:
Class of Threats
The National Electric Code (NEC), SS667:2020 Code of practice for handling, storage and processing of combustible dust and NFPA 654:2017 Standard for the Prevention of Fire and Dust Explosions, define hazardous environment combustible dusts and flammable gases and vapours into three separate Classes.
- Class I locations are categorised by the flammable gases and vapours present in industries such as natural gas, petroleum and chemical.
- Class II locations contain combustible dusts. These dusts can be carried aloft during pulverising processes or compacted in storage centres. Combustible dusts are found inside plastic, pharmaceutical, coal and agricultural (grain and flour) processing locations.
- Class III locations contain the ignitable fibres and flyings that are produced in the wood, cotton, and textile industries, among others.
Defining the Presence with Divisions
The National Electric Code (NEC), SS667:2020 Code of practice for handling, storage and processing of combustible dust and NFPA 654:2017 Standard for the Prevention of Fire and Dust Explosions, define hazardous environments by the amount of exposure to the gases, vapours, or dusts as illustrated below:
- Division 1 classifies hazardous atmospheres in which the flammable gas or vapour or combustible dust is present during normal operations or routine maintenance. The existing or potentially hazardous atmosphere must also be in the right mixture concentrations to be ignitable. Thus, proper ventilation can change a Division 1 location into a Division 2 location.
- Division 2 locations are where hazards are encountered only during an abnormal situation, such as equipment failure or a spill. Locations adjacent to Class I, Division 1 areas may be deemed Division 2 as well, to accommodate for the potential seeping of gases or vapours.
Groups within Each Class
Class ratings are further broken down into material groups, which identify the explosive characteristics of the material. The volatility of these groupings are based on Maximum Experimental Safe Gap (MESG) and Minimum Ignition Current (MIC) as below:
Class I locations consist of Groups A, B, C and D:
- Group A, acetylene, features the highest outward pressure during an explosion
- Group B is hydrogen
- Group C is ethylene
- Group D is gasoline
Class II locations are divided into three Groups, E, F, and G in accordance with NFPA499, as below:
- Group E is combustible metal dust such as aluminium and magnesium
- Group F consists of coal, printer ink powder and coke
- Group G features agricultural dusts such as cake mix, grain dust and flour
The National Electric Code (NEC), SS667:2020 Code of practice for handling, storage and processing of combustible dust and NFPA 654:2017 Standard for the Prevention of Fire and Dust Explosions, define hazardous environments by the Work Zones which are similar to the Divisions, except that they classify three levels of the existence of hazardous atmospheres instead of two as below:
- Zone 0: hazardous atmospheres are continuously present
- Zone 1: hazardous atmosphere is often present
- Zone 2: hazardous atmosphere may accidentally be present
The following are some essential key points to consider in your plans to determine your lighting design for ATEX areas.
- The geographical location of production and process facilities.
- Context and Scope of Work (SoW) – An explanation in simple terms of the activities undertaken within the production and process facilities.
- Any hazardous substances, particles, vapours, combustible dusts and flammable gases that may be present or are likely to be present within the production and process facilities which could give rise to a major accident, with an indication of their principal dangerous characteristics.
- General information relating to the nature of the major accident hazards within the production and process facilities, including their potential effects on individuals and workplaces.
- Information on how affected workplaces will be alerted in the event of a major accident within the production and process facilities.
- Recommended continuity plans and actions that the affected workplaces can take in the event of a major accident within the production and process facilities.
- Laboratory testing of lighting fixture mock-ups by suppliers/vendors.
- Devising a Safety Risk Management Register.
- Training a Product Inspector – The IECEx Certified Persons Scheme provides the global Ex industries with a single system for the assessment and qualification of persons meeting the competency prerequisites needed to properly implement the safety requirements based on the suite of IEC International Standards covering explosive atmospheres, e.g. the IEC 60079 and IEC 61241 series of standards.