LEV Testing to HSG258
Certified LEV testing for all types of extraction systems across the UK
What is LEV Testing?
LEV systems are designed to capture and remove airborne contaminants such as fumes, vapours, dust, and gases at the source. Regular LEV testing is a legal requirement under the Control of Substances Hazardous to Health (COSHH) Regulations 2002.
Employers must ensure their LEV systems are thoroughly examined and tested at least once every 14 months — or more frequently depending on usage and risk.
What is HSG258?
HSG258 is the Health and Safety Executive’s official guidance document titled “Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV).” It outlines best practices for designing, installing, maintaining, and testing LEV systems to ensure they control worker exposure to harmful substances effectively.
The guidance is intended for employers, designers, managers, engineers, and anyone responsible for controlling airborne hazards in the workplace. HSG258 provides detailed advice on system selection, airflow performance, control verification, and how to ensure continued effectiveness through regular testing and maintenance.
What Needs to Be LEV Tested?
All systems that extract hazardous fumes, dusts, vapours or other airborne contaminants are considered LEV and require statutory testing. This includes systems found in laboratories, manufacturing facilities, and even commercial settings.
Common LEV systems that require testing include:
• Workshop machine extract systems (e.g. wood dust, metalworking fumes)
• Nail bar extraction hoods and beauty salon fume systems
• Welding and soldering fume extractors
• Spray booth and paint extraction systems
• Dust and fume extraction units in construction, food processing, and manufacturing
• Vehicle exhaust systems
• Electroplating and metal finishing workshops
• Bench-top arms and flexible hose extract systems
• Laboratory fume cupboards and ducted extract systems are also considered to be LEV systems, although they are more frequently tested to the specific requirements of BS EN 14175 (Laboratory Fume Cupboards, or CLEAPSS G9 (School Fume Cupboards)
If your workplace has any equipment or processes that release airborne contaminants, it is likely that an LEV system is required — and must be tested at least annually.
Testing to HSG258 Guidelines
HSG258 is the Health and Safety Executive’s guidance for the design, maintenance and testing of LEV systems. Our BOHS P601 qualified engineers follow this standard to assess whether your system is effectively controlling exposure to hazardous substances.
Testing typically includes:
• Airflow measurement and hood face velocity testing
• Visual inspection of ductwork, fan, stack and control equipment
• In-duct velocity readings and volume calculations
• Smoke tests to verify capture performance
• Static pressure checks and filter assessments
• System condition review and performance grading
We provide a full LEV test report and certificate for your records and HSE compliance audits.
Why is LEV Testing Important?
LEV systems degrade over time due to wear and tear, blockages, damage or filter failure.
Without testing, workers could be exposed to hazardous substances, leading to potential health risks and regulatory non-compliance.
Regular testing helps identify issues early, maintain system efficiency, and demonstrate due diligence.
Why Choose Fumair for LEV testing?
• BOHS P601 qualified LEV test engineers
• Nationwide service coverage
• 50+ years of experience with laboratory and industrial systems
• Clear, COSHH-compliant test reports
• Support for all types and manufacturers of LEV systems
• We do not just test, we can identify the faults and fix them too
