Understanding HSG258 – Controlling Airborne Contaminants at Work

HSG258: Controlling Airborne Contaminants at Work is one of the Health and Safety Executive's (HSE) key guidance documents for employers who use Local Exhaust Ventilation (LEV) to control hazardous airborne substances.

It provides practical guidance on how LEV systems should be designed, installed, commissioned, used, maintained and tested to effectively protect employees from exposure to hazardous dusts, fumes, vapours, mists and gases.

At A-Mac Environmental, we help businesses apply the principles of HSG258 by designing, installing, testing and maintaining high-performance LEV systems that improve workplace air quality and support compliance with COSHH Regulations.

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What is HSG258?

HSG258 is official guidance published by the Health and Safety Executive (HSE).

Although HSG258 is guidance rather than legislation, it explains recognised good practice for complying with the legal duties set out in the Control of Substances Hazardous to Health (COSHH) Regulations.

Following HSG258 helps employers demonstrate that they are taking appropriate steps to control employee exposure to hazardous airborne contaminants.

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Why is HSG258 Important?

Many workplaces generate hazardous airborne contaminants during everyday activities, including:

• Welding fumes

• Wood dust

• Flour dust

• Metal dust

• Silica dust

• Oil mist

• Vehicle exhaust emissions

• Chemical vapours

• Paint spraying

• Laboratory fumes

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Without effective control, these contaminants can affect employee health and increase the risk of long-term occupational illnesses.

HSG258 provides practical guidance on ensuring LEV systems effectively capture these contaminants before they reach employees' breathing zone.

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What Does HSG258 Cover?

HSG258 provides guidance on every stage of an LEV system's life, including:

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• Risk Assessment

Understanding the hazardous substances generated within your workplace and identifying the most appropriate control measures.

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• LEV System Design

Designing systems that effectively capture airborne contaminants at source while maintaining suitable airflow throughout the system.

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• Installation & Commissioning

Ensuring the system is correctly installed and performs as intended before being put into service.

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• User Training

Making sure employees understand how to operate LEV equipment correctly and recognise when systems are not performing as expected.

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• Inspection & Maintenance

Regular servicing, filter replacement and maintenance are essential to ensure the system continues to operate efficiently.

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• Thorough Examination & Test (TExT)

Most LEV systems require a Thorough Examination and Test (TExT) at least every 14 months, unless more frequent testing is required due to the nature of the process or the substances being controlled.

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The Principles of Good LEV

A well-designed LEV system should:

• Capture contaminants as close to the source as possible

• Prevent hazardous substances from entering the breathing zone

• Transport contaminated air efficiently through the ductwork

• Remove contaminants using suitable filtration where required

• Discharge cleaned or extracted air safely

• Be easy to inspect, maintain and test

• Continue performing consistently throughout its service life

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These principles form the foundation of effective airborne contaminant control.

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Industries That Benefit from HSG258 Guidance

HSG258 applies across a wide range of industries, including:

• Manufacturing

• Engineering

• Welding and fabrication

• Woodworking and joinery

• Food production

• Commercial bakeries

• Pharmaceutical manufacturing

• Healthcare

• Automotive workshops

• Distilleries and breweries

• Education and research laboratories

• Chemical processing

• Printing and packaging

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Where hazardous airborne contaminants are present, HSG258 provides valuable guidance on achieving effective control.

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How A-Mac Environmental Helps You Meet HSG258 Best Practice

A-Mac Environmental provides complete LEV services designed in line with HSG258 guidance, including:

• LEV system design

• Supply and installation

• LEV commissioning

• Thorough Examination and Test (TExT)

• Planned preventative maintenance

• LEV servicing

• System upgrades

• Airflow performance testing

• Technical advice and compliance support

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Our qualified P601 and P602 engineers work with businesses throughout Scotland to ensure their LEV systems continue to operate safely, efficiently and effectively.

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Frequently Asked Questions

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Is HSG258 a legal requirement?

HSG258 is official HSE guidance rather than legislation. However, it explains recognised good practice for complying with the legal duties set out in the COSHH Regulations. Following HSG258 helps businesses demonstrate that they are effectively controlling exposure to hazardous airborne contaminants.

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Does every LEV system need to follow HSG258?

Any workplace that uses LEV to control hazardous airborne substances should consider the principles and guidance in HSG258 to ensure that systems are effective and properly maintained.

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How often should an LEV system be tested?

Most LEV systems require a Thorough Examination and Test (TExT) at least every 14 months. Some systems, particularly those controlling highly hazardous substances, may require more frequent examinations.

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What is the difference between COSHH and HSG258?

COSHH is the legislation that requires employers to control exposure to hazardous substances.

HSG258 is the HSE guidance document that explains how to achieve effective control using Local Exhaust Ventilation (LEV).

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Can A-Mac Environmental help with HSG258 compliance?

Yes. We provide complete LEV design, installation, testing, servicing and maintenance services to help businesses apply the principles of HSG258 and maintain effective control of airborne contaminants.

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If you're unsure whether your LEV system meets the principles of HSG258, A-Mac Environmental can help.

Our experienced engineers provide professional LEV design, installation, Thorough Examination and Test (TExT), maintenance and compliance support for businesses throughout Scotland.

Contact us today to discuss how we can help improve your workplace air quality and ensure your LEV system continues to perform safely and effectively.