What is a LEV system?
A Local Exhaust Ventilation (LEV) system controls and captures harmful airborne dust, fumes and vapours that could contaminate the air. The LEV system extracts these toxic substances from the worker’s breathing zone, cleans them, and then safely discharges them into the atmosphere. Simply put, a LEV is a device that removes airborne contaminants from the workplace.
A LEV comprises five key components:
Hood – captures contaminated air. It needs to be as close as possible to the source of contamination to ensure it can capture and draw in as much air as possible. Ideally, the hood should enclose the area to prevent draughts from blowing contaminated air away from the site.
Ducting – the contaminated air travels through the ducting before being taken to the air cleaner. It is essential that the ducting has no sharp corners and that all bends are smooth. This is because sharp bends can reduce airflow in the duct and make it harder for contaminated air to reach the air cleaner.
Air cleaner – filters contaminated air. Choosing the right filter for your needs is essential; it must be regularly cleaned to keep working efficiently.
Fan – the fan moves the contaminated air through the hood, ducting and air cleaner before taking it to the exhaust stack.
Exhaust stack – releases the filtered air back outside. The exhaust stack must be positioned on an outside wall. It is also important to note that it should be kept away from public areas or air conditioning systems to prevent contamination elsewhere.
What is RPE?
Respiratory protective equipment (RPE) is a type of Personal Protective Equipment (PPE) that uses filters to protect the wearer from inhaling harmful substances. RPE only protects individual workers from toxic substances.
Types of RPE:
Non-powered respirators – The non-powered respirators rely on the wearer’s breathing to draw air through the filter.
Powered respirators – Powered air-purifying respirators (PAPRs) use a motor to draw air through a filter, providing the wearer with clean air.
Breathing Apparatus – supplies clean air from a gas cylinder or an air compressor.
The above types of RPE fit into two main groups: tight-fitting and loose-fitting masks. Tight-fitting masks rely on having a good seal on the wearer’s face. Loose-fitting masks rely on enough clean air so that no contaminants can get in.
Why do you need LEV systems and RPE?
RPE is designed to protect the individual wearer by reducing their risk through clean air. A LEV system works by removing harmful substances from the atmosphere, thereby reducing the likelihood that anyone will inhale them. Ideally, the two should be used together to provide a safe environment for the worker and others around them.
Thousands of people develop occupational diseases each year from breathing harmful dust and fumes in the workplace. The problems caused by breathing in these toxic substances are not necessarily felt straight away, and it often takes years before any symptoms present themselves. By the time the symptoms show, the problem is often irreversible.
Employers must take proper precautions to control harmful fumes and prevent long-term health problems such as asthma, lung scarring, and cancer. Installing LEVs and providing RPE are great ways to do this and can help reduce the effects of these harmful substances.
How does D&M protect its employees?
D&M provides both LEV systems and RPE to our employees. This protects employees who work with harmful substances and everyone in the surrounding area. We provide RPE and LEV systems to our welding, powder coating, deburring and metal finishing departments to ensure they are protected.
How do we protect our employees from weld fumes?
We provide all our welders with their own air-fed masks, and each station has access to the LEV system. We train our welders to perform pre-use checks before welding, which helps reduce weld fumes. The checks include the following:
- Removing grease and surface coatings before welding, as these may release toxic components when heated.
- Position the workpiece and LEV hood to reduce exposure to the fumes.
- Keep workbenches free of clutter to prevent air from being restricted.
Our employees conduct daily visual checks of the LEV systems to ensure they appear to be working correctly and that there are no visible tears in the ducting. We regularly change the filters, and our LEV systems are inspected/serviced by a specialist company at the required intervals. This way, we know the systems we have put in place are working correctly and protecting our staff from hazardous materials. We also train staff on how to use the LEV systems, including things such as:
- Ensuring the fume is drawn away from them and not towards them by the LEV
- Position the LEV hood close to the welding point to collect fume effectively.
- Position the workpiece correctly on the bench to ensure corrective capture of fumes.
- If using a turntable or bespoke jig, ensure it is positioned to take fumes away.
D&M provides all our welders with their own air-fed masks as RPE; these must be worn at all times during welding to ensure protection from weld fumes. We recommend the following when it comes to wearing RPE:
- RPE must be worn at all times when welding processes generate significant fumes.
- RPE must be used if the size or shape of the workpiece being welded means the LEV provided cannot provide reliable, consistent fume control for all welds.
- RPE must be used when welding outdoors.
- RPE must be checked before every use and cleaned after every use.
- Report any RPE issues immediately to our health and safety manager.
Our store manager ensures that all RPEs are cleaned and maintained after each use, keeping the masks in constant working order. We also recommend that, if there is significant weld fume build-up, our roller doors be opened to provide additional ventilation into the workshop. As extra precautions, we follow the Department of Health guidelines and recommend that our welders receive a pneumococcal polysaccharide vaccine from their GP. D&M provides a letter for them to take to their GP and will cover the cost if required.
Here at D&M, we take our employees’ safety seriously and work hard to ensure that all our staff are protected from harmful substances whilst at work.