Fume & Dust Extraction

In Great Britain, the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) require employers to eliminate or control the risks from explosive atmospheres in the workplace. This includes adhering to two European Directives including Directive 2014/34/EU, also known as the ATEX Equipment Directive, which concerns equipment and protective systems intended for use in potentially explosive atmospheres. 

Production facilities that use combustible powders as part of their production process, or those which create a very fine waste which is classed as combustible dust, should all use ATEX rated equipment.

Kerstar’s UK manufactured ATEX certified industrial vacuum cleaners are suitable for use in Gas Zones 1 and Dust Zones 21 & 22 – as specified on the rating plate on every unit. All of Kerstar’s compressed air (KAV range) and electric (KEVA range) ATEX vacuums provide three-stage filtration which includes a specially designed microfibre bag with a cap which, when closed, cannot be re-opened, and a HEPA H14 filter – offering 99.995% efficiency for dusts and powders as fine as 0.3 micron.

All KAV and KEVA models offer stainless steel canisters mounted on a stainless steel caddy fitted with conductive braked castors and wheels - this ensures each vacuum is antistatic and conductive from top to bottom. Every machine is supplied with a fully conductive hose and accessory kit, and a full earth path continuity certificate.

Kerstar Business Development Manager, Brian Folland, comments, “It’s really important that employers ensure they are providing equipment which is fit for purpose – particularly in potentially explosive atmospheres. This is just as important for cleaning equipment as it is for production machinery. Everything used in an ATEX rated Zone must be certified to meet the ATEX Directives.”

Find out more about Kerstar’s ATEX certified and Type H (suitable for use with hazardous dusts) vacuum cleaners by visiting www.kerstar.com.

In industrial settings, laboratories, and workplaces where hazardous airborne particulates pose a significant threat, the importance of efficient air management cannot be overstated. Aerially transported contaminants, such as dust, fumes, and pollutants, can not only compromise the health and safety of workers but also have adverse effects on the environment. To address these challenges, ducting systems emerge as a critical solution, providing various benefits.

From containing contaminants at their source to facilitating proper ventilation and filtration, these systems are indispensable in safeguarding both workers and the environment. By adhering to industry regulations and promoting worker safety, ducting offers a proactive approach to tackling airborne hazards and fostering a healthier work environment.

What is ducting used for?

Ducting, or ductwork, is used for various purposes across different industries and settings. It is a system of channels or conduits designed to convey air, gases, liquids, or other substances from one location to another. Ducting serves several essential functions, including:

1. HVAC (Heating, ventilation, and air conditioning): Ducting is a fundamental component of HVAC systems. It distributes heated or cooled air throughout buildings and helps maintain a comfortable indoor climate. Air is drawn from rooms, passed through ducts, conditioned (heated or cooled), and delivered back to different areas.

2. Ventilation: Ducting facilitates ventilation in enclosed spaces by extracting stale or polluted air and replacing it with fresh outdoor air. They improve indoor air quality and create a healthier environment for occupants.

3. Exhaust systems: It is used in exhaust systems that remove unwanted air, fumes, or pollutants from industrial processes, laboratories, kitchens, and other areas where airborne contaminants are produced.

4. Dust and particle collection: In industrial settings, ducting is utilised to collect and transport dust, particles, and debris away from workspaces. This helps maintain a cleaner and safer environment for workers and machinery.

5. Filtration: These systems often incorporate filters to trap and remove particulates, allergens, and pollutants from the air.

6. Process piping: In some applications, ducting functions as a tube for transporting gases or liquids during industrial processes.

7. Environmental control: Ducting helps regulate humidity levels in indoor spaces, which is particularly important for environments like data centres and certain manufacturing facilities.

8. Smoke extraction: In the event of fires, ducting can extract smoke and direct it outside, helping occupants evacuate safely and assisting firefighters in managing the situation.

9. Cleanrooms: Ducting is employed in cleanroom environments to maintain controlled and filtered air, ensuring minimal contamination during manufacturing processes or scientific research.

10. Air distribution: It distributes air evenly in large commercial or industrial buildings, ensuring consistent airflow and temperature throughout the space.

Ducting comes in various shapes, sizes, and materials, depending on the specific application and the substance being conveyed.

Examples of hazardous airborne particulates

Hazardous airborne particulates are tiny solid or liquid particles suspended in the air that can pose risks to our health and the environment. These particles can be produced naturally or by various human activities. Some examples include dust, mould, asbestos, lead particles, pollen grains, silica, diesel emissions and smoke particles.

Fine dust consists of tiny particles with a diameter of 2.5 micrometres or smaller. These particles can originate from various sources, such as vehicle emissions, industrial processes, and wildfires.

Mould spores can be found in various indoor environments. Inhaling them can lead to respiratory issues, particularly for individuals with allergies or asthma.

Asbestos is a mineral that was widely used in building materials. Disturbance of asbestos can release microscopic fibres that, when breathed in, can cause severe lung diseases.

Lead particles are present in the air around industrial sites or from deteriorating lead-based paint in older buildings. Inhalation of lead particles can aggravate and contribute to neurological and developmental problems.

Pollen grains are released by various plants. They can become airborne and trigger allergic reactions in susceptible individuals.

Silica is a naturally occurring mineral found in sand, rocks, and soil. Activities such as construction or mining can disturb silica, generating fine dust that can cause respiratory issues if inhaled.

Diesel exhaust particles are emitted by vehicle engines. They contribute to air pollution and potential respiratory problems.

Finally, smoke generated by wildfires or burning materials (including cigarettes) can release fine particulates that pose health risks when taken in.

Factors that may affect the ducting system's performance

iDuct, a provider of ducting solutions with over 40 years of experience, alerts that several key factors come into play when evaluating a ducting system's capabilities.

One crucial aspect is the choice of material, which should be carefully selected to withstand the corrosive or abrasive nature of different dangerous particulates.

The size and design of the ducts, along with the placement and design of extraction hoods, also play vital roles in ensuring efficient containment and extraction.

Proper sealing of duct joints and connections is essential to prevent leaks and maintain system efficiency. Additionally, airflow velocity, filtration system effectiveness, and precautions against static electricity hazards are critical considerations. Regular cleaning and maintenance, along with monitoring mechanisms, further enhance the system's performance. Understanding and accounting for environmental factors are also necessary for optimal effectiveness.

Addressing these elements creates a safer working environment and mitigates potential risks associated with hazardous particulates.

We spoke to Daniel Frith, Operations Manager at UK’s leading safety company, Arco, about the dangers of exposure to airborne contaminants and how to mitigate the risks. 

How can workers be exposed to airborne contaminants? 

Daniel Frith: Airborne contaminants can occur from a variety of outputs depending on the occupational setting via substances such as dust, gases, fumes, mists, or vapours present in the air. As a result, some industries are more susceptible to the presence of harmful substances such as construction, manufacturing and mining. Manufacturing roles such as brick and tile manufacture, ceramics and stone working, foundry work are particularly prone to harmful effects, even dusts created by foodstuffs that we consider to be safe can be hazardous, if there is continuous exposure. Output is often invisible to the naked eye, and workers are not aware that they are exposed.  

 

What are the dangers of being exposed to these kind of hazardous substances? 

Daniel Frith: Every year, thousands of workers in the UK experience damaging lung-related effects from airborne contaminants such as lung cancer, asthma or lung scarring because of airborne contaminants they have breathed in at work. In 2022, there was an estimated 19,000 new cases of breathing or lung problems made worse by work, according to the HSE. The severity of harmful effects will ultimately depend on duration, frequency and degree of exposure to the substances. 

Is it difficult to control exposure to airborne contaminants? 

Daniel Frith: As a result of the variety of airborne contaminant transmission and the often-imperceptible output, the HSE has identified a concerning trend: that employers are often unaware that their workers are being exposed to hazardous substances or that their existing controls may be insufficient. This lack of awareness gives rise to several issues including the sources of exposure being missed, the deterioration of existing controls and incorrect utilisation of the implemented safeguards.  

What is the law on protecting workers from harmful exposure? 

Daniel Frith: The UK has a strong framework and reputation when it comes to health and safety and the approach towards airborne contaminants is no exception. The primary legislation that addresses harmful airborne contaminants in the workplace is the Control of Substances Hazardous to Health Regulations (COSHH) which outlines that employers have a legal duty to access risks associated with hazardous substances and make decisions on what measures to use to protect the health of their employees. It is important that employers are engaged with airborne hazard safety not only for the health of their employees but to also avoid enforcement action. 

 

What do employers need to do to eliminate the risk and protect workers? 

Daniel Frith: Employers can use the Hierarchy of Control as a way to determine which actions are most necessary to control hazards in the workplace. The first level of control is the elimination of the hazard entirely - removing a toxic chemical for example. The second level is substitution and involves offering a safer alternative to the hazardous substance. The first two actions can be the most difficult to adopt for reasons such as cost and design and so the third level - local exhaust ventilation systems (LEV) - is the level of control used most often. The use of LEV isolates workers from the hazard by removing the substance at the source. The fourth level is administrative controls such as reducing the frequency of exposure to hazards. The fifth and final level is the use of personal protection equipment (PPE) such as gloves and masks to minimise exposure to hazards. Levels four and five are useful actions but should be combined with other control methods to offer the most protection. 

What is the process for installing LEV into the workplace? 

Daniel Frith: There is a systematic approach to installing LEV in the workplace to make sure that it is fit for purpose and effective. The first step is a risk assessment - anticipating, recognising, evaluating and controlling the hazards. It is advisable to engage with an expert throughout this process so that the most suitable methods are chosen - installing an ineffective system can be very costly. Arco Professional Safety Services can offer risk assessment guidance and support businesses to identify workplace hazards and implement practical measures to eliminate or reduce them. Undertaking a comprehensive COSHH assessment and workplace air monitoring can help you to identify your hazardous substance/s, evaluate the usage risks, determine the required control measures and ensure they are working effectively. 

How often do LEV systems need to be monitored and checked? 

Daniel Frith: Regular inspections of LEV systems should take place to ensure the smooth running of the device. A Periodic Test Examination (TExT) should be conducted at least every 14 months with records kept for at least five years. This requires a competent examiner who has the correct knowledge, skills and practical experience and can be conducted by a trained employee or an outside contractor. Detailed information from the examination should be kept for the lifespan of the LEV system.  Business owners should work with an expert safety partner to ensure systems are compliant.   At Arco we have a dedicated team with the knowledge and experience to produce a 14-monthly TExT Report to ensure you remain compliant to COSHH Regulations and that equipment is in good working order and provides the necessary protection. 

To read more on LEV, please visit Arco’s advice page: https://www.arco.co.uk/expert-advice/hose/LEV or contact us on: 01482 383288 or email This email address is being protected from spambots. You need JavaScript enabled to view it. 

This article can also be found in the issue below.

 

 

Hydrogen is a colourless, odourless, and tasteless gas, therefore small gaseous leaks are difficult to detect by human senses. Small leaks are common due to the small size of hydrogen molecules and usually do not present a problem since the tiny amount of mixture will not be enough to cause a flammable mixture in the air. Small amounts of leaking hydrogen will rise and diffuse quickly in air because of its low density resulting in high buoyancy (it’s 14 times less dense than air).

Hydrogen is less likely to cause a fire or explosion hazard in an open or well-ventilated space, but a problem arises when hydrogen gas is allowed to accumulate in a confined area. If this is allowed to happen, there will be a risk of a flammable mixture building up. When a large amount of accumulated hydrogen rises and mixes readily with air, it creates an ignitable mixture that can result in flames or explosions. Hydrogen is flammable in air at a volume of 4-75% by volume. 

Any structure that contains hydrogen components should be ventilated adequately. Since hydrogen is lighter than air, it collects under roofs and overhangs. Most people are familiar with protecting plants from heavier than air vapours, but are unfamiliar with upward issues. There have been many reports of hydrogen leaks igniting over the decades, and several potential ignition prevention mechanisms and hydrogen leak detection systems have been proposed. 

Methods for hydrogen leak detection include:

Reducing the Volumetric ratio of Hydrogen to Air

Ignition can occur at a volumetric ratio of hydrogen to air as low as 4% due to the oxygen in the air and the simplicity and chemical properties of the reaction. 

The best practice to avoid accumulation is to determine where hydrogen leaks are likely to occur and how they may disperse and ventilate accordingly to manage the airflows sufficiently to keep hydrogen concentrations below the lower flammability level(LFL) during probable release scenarios. Ventilation rates should be sufficient to dilute hydrogen leaks to less than 25% of the LFL which is about 1% volume by air. The minimum ventilation rate should safely dilute hydrogen build-up in the event of leakage and the ventilation should not shut down in emergency or during periods of shut down. 

It is generally safe to exhaust hydrogen into open atmosphere providing it is kept high enough that the heat does not harm anyone. Ventilation systems should not be used for the disposal of hydrogen; this should be managed by a separate system called a vent system. 

IIC Fans for Potentially Explosive Environments

Hydrogen is a gas group IIC gas and belongs to the T1 temperature class making it one of the hottest, most dangerous gases. Mechanical exhaust fans should be ATEX rated to the appropriate IIB+H2 or IIC T1 ATEX certification andconstructed from the suitable permissible material pairings as noted in the current legislation surrounding equipment for explosive environments. Material pairings should specifically relate to the rotating and stationary parts that may come into contact with each other during standard or rare malfunction. This material pairing reduces the risk of ignition created from friction and the build up of static electricity to create a spark. ATEX fans are therefore often referred to as having a spark proof construction. 

Our entire range of ATEX certified fans are suitable for gas group IIC or IIB + Hydrogen applications for effective hydrogen ventilation. Learn more by visiting our website. 

www.axair-fans.co.uk

Mechanical sparks and friction are one of the most common causes of ignition of flammable gases and dust clouds. Accident statistics in Germany indicate that mechanical sparks and friction as an ignition source occurred in 32.7% of incidents.

Incorrectly selected, or fans deemed unsuitable for hazardous areas, can produce an effective ignition source caused by various incidents; hot surfaces, by mechanically generated sparks because of friction, impact, or abrasion processes (because of contact between the rotor – the rotating part, and fixed components) or by the electric discharge of static electricity when using non-conductive materials.

In the normal operation, or in the event of malfunctions (whether standard or rare), possible friction caused by areas meeting one another can occur. As stated in the ATEX directive and adopted into UK legislation, potential areas of contact between the rotating elements and fixed components of equipment for use in potentially explosive environments, should be manufactured from materials in which the risk of ignition caused by friction and friction impact sparks, hot spots or hot surfaces is minimised. This applies specifically to the construction and manufacture of explosion proof industrial fans. Ignition risks cannot be completely eliminated but can be significantly reduced by taking suitable constructive measures for avoiding ignition sources.  

European and UK Directives are clear on the permissible material pairings that are suitable to reduce the ignition source caused by friction of rotating and fixed component parts. Material pairings are considered carefully by fan manufacturers and authorised bodies. They use their theoretical and practical knowledge, coupled with the known application conditions for the environment in question, the safest material pairing and other compulsory technical specifications to determine how a product is chosen for an explosive environment.

Material pairings are devised and communicated in legislationdocumentation to minimise the risk of an explosion. Industrial fans in systems or machinery, are generally not supervised continuously and contact between rotating and stationary orfixed components, may occur in a particular area for an unknown amount of time, potentially in long intervals. 

Metal to Metal Ignition

Metal to metal ignition is caused either by rubbing friction, as mentioned earlier, such as between a rotating impeller and a stationary piece of metal, or by impact of two metal objects. Research has shown that in metal-to-metal contact, the properties of the more readily oxidised metal, normally determine the degree of ignition hazard. The hardness, melting point, ignition temperature, specific heat conductivity and brittleness of the metals all play a role, in that they determine the size, duration, temperature and heat capacity of the incendive sparks. 

An important precondition for all the protection principles is that parts which are in unhindered contact with the explosive atmosphere must not be able to reach non-permitted high temperatures with respect to the ignition temperature of substances present in the site of installation. This means that the ignition temperature is relevant for all protection principles. We cover temperature classes and surface temperature on our website.

The standard EN14986 dictates minimum design rules that industrial fans for hazardous areas should comply with. In relation to the material pairings that we introduced earlier, the below briefly seeks to improve your knowledge of the parts of ATEX fans that indicate the rotating and stationary parts that must be manufactured from these permissible materials to reduce the risk of sparks and hot spots due to frictional rubbing in the event of movement between the two parts. For more information on a wide range of ATEX topics please visit our website.

ATEX Axial Fans 

In axial fans the two parts are:

Rotating: Impeller, tip of the blades.

Stationary: The fan casing & ring

www.axair-fans.co.uk

This article can also be found in the Jan/Feb isuse.

 

  

Based in Helsingborg, Sweden, Nederman is a global player in working environment products and systems. Over 60 years of experience have helped the Group develop a modern and extensive product range.

Nederman is a world leader in dust and smoke extraction, exhaust fume extraction, hose and cable reels and workplace partitioning.
With sales in more than 50 countries and its own distribution network, Nederman is the best-known brand in the industry on a global basis.

The October edition of EMS magazine is now available to read online in page turning digital format or PDF format. This edition contains articles on achieving best practice in condition monitoring and plant maintenance as well as the latest products, news and case studies.

We introduce our 'unique' Explosion Proof Mobile Dust Extraction unit which is 'LEGALLY' certified ATEX Zone 21 and Zone 1 (Gas/Dust). Constructed in Stainless Steel (other materials available), it is the only Mobile unit available with this certification. Ideal for Pharmaceutical/Medical, Food industries as it has full HEPA filtration and is cleanroom compatible.

Suitable with:

•    3 metre long 304 grade S/S dust extraction arm
•    2500m3/hr centrifugal fan with 1.5kw EExd II B T5 Motor
•    9m2 multi pocket, anti static, polyester needlefelt bag filter
•    Automatic filter cleaning by timed shaker with 0.55kw EExd II B T5 Motor
•    Secondary HEPA filtration
•    Dust collection bin
•    Electrical control panel requireing 415v 3ph supply
•    304 grade S/S construction

ARC Technologies, is the authorised distributor for ‘Tiger-Vac’ ATEX rated Industrial Vacuum Cleaner Systems for wet or dry recovery. ’ LEGALLY’ Certified for hazardous locations:  Fuel, metal dust, pharmaceutical powder, shooting ranges, flour mills, carbon black, nuclear, etc.

These vacuum cleaner systems are certified for explosion proof / ignition proof hazardous locations by an independent lab and can be used to vacuum up flammable and explosive materials. Qualified for categories 1, 2, & 3 as defined in the ATEX directive 94 / 9 /EC.