top of page

Introduction to COSHH

Updated: Apr 17, 2020

Control of Substances Hazardous to Health - A Step-by step guide to COSHH

As always, we aim to provide some basic principles of occupational hygiene practices to help and support our wider community of occupational health and safety professionals providing information from an occupational hygiene / industrial hygiene perspective.

Introducing COSHH

Chances are, as a health and safety professional (or health and safety-conscious individual) you've come across the term COSHH. Additionally, you would have come across controls using extraction, respirators, chemical resistant gloves, coveralls and so on. You will have also come across the term "risk assessment", particularly one focused solely on COSHH. The aim of this article is to build awareness around this element of occupational hygiene and show how all of these fit together under the "COSHH Spectrum".

Lets start with explaining what we do as Occupational Hygiene professionals...

Occupational hygiene is the health and safety specialism concerned with the anticipation, recognition, evaluation and control of chemical, physical and biological agents in the workplace and brings together disciplines including science, mathematics and engineering to understand personal exposure to workplace hazards and implement adequate control solutions.

Regarding COSHH, Occupational Hygienists undergo a thorough assessment of the workplace using a variety of evaluation and measurement tools. Which include,

  • Carrying out COSHH Risk Assessments (Substance or Process-Based)

  • Undergoing Workplace Air Monitoring

  • Undertaking Biological Monitoring

  • Evaluating Current Control Measures and Their Efficiencies (LEV Thorough Examination and Testing)

  • Health Surveillance (Skin Checks, Health Assessments, Lung Function Testing)

1.COSHH Risk Assessment

Before we can quantify or control personal exposure to chemical agents we must first understand the foreseeable risks. This is determined through risk assessment.

A COSHH risk assessment brings together several components to determine the risk and provide a list of required actions. In brief, these components include an understanding of the substances involved, how they are used and by whom, what the routes of exposure are and what control measures are currently being used such as fume cupboards and gloves.

Recommendations for exposure monitoring or further controls are based on the foreseeable risk outlined in this assessment.

2. Workplace Exposure Monitoring - used to quantify the foreseeable risk by sampling for contaminants which have entered the body

This can be undertaken in two forms; workplace air monitoring which demonstrates the personal exposure risk via inhalation or biological monitoring which identifies the total uptake of the body by all routes of exposure including inhalation, ingestion and skin contact.

3.Applying the Hierarchy of Control

Once the foreseeable risks have been identified and quantified it is time to prevent, or where this is not possible, reduce personal exposure to the substances of concern as low as reasonably practicable.

This is achieved through the principles of the Hierarchy of Control which is a hierarchy of technical and procedural measures which, at its most effective, removes the substance from the workplace all together whereas at its least effective only controls exposure on an individual basis.

One of the main methods of exposure control is that of local exhaust ventilation (LEV)...

Workplace Scientifics, Air Quality Sensor, Indoor Air Quality Monitor, Pollution Monitoring, Air Quality Detector, Air Pollution Meter, COSHH Regulations, COSHH Assessment, COSHH Training, COSHH Risk Assessment, COSHH Legislation, Occupational Health and Hygiene, Occupational Hygiene Monitoring, Occupational Hygiene Services, Industrial Hygiene and Safety Services, Occupational Health and Hygiene, LEV, Welding Fume, Exposure Control, TEXT, Thorough Examination and Testing, Occupational Hygiene, Industrial Hygiene.
LEV Systems should undergo a thorough examination and test under COSHH Regulations.

LEV is an engineering solution that comes in all different shapes, sizes and applications.

The key here is to know how the substance needs to be controlled. For example, if the substance is a hot, buoyant vapour you may wish to look at a receptor style hood or if it is a dust you may find a capture hood is more suitable.

The overall principle of LEV is to remove the substance from the breathing zone of the worker as well as away from the general working population. Training on its use is just as important as its design.

Applying a Suitable RPE Program

An apparently favoured method of control (but shouldn't be regarded as the primary control) is that of respiratory protective equipment (RPE). Again, RPE can come in all different shapes, sizes and applications and, as it is a ‘personal’ measure, the correct selection of such a device is critical for it to offer the user the required level of protection.

When selecting RPE considerations should be made for:

  • The substances used.

  • How the substances are used (routes of exposure) - does further protection of the skin need to be taken into consideration in addition to respiratory protection?

  • Facial anthropometrics - does the RPE provide adequate protection due to a tight seal?

  • The application of a fit test - has the effectiveness been adequately assessed by undertaking RPE Face Fit Testing by a competent person.

Think about what can be done to achieve residual risk before RPE is applied...

Administrative control measures should be considered to help reduce exposure to substances hazardous to health. Safety professionals or responsible people could consider the following administrative controls:

  • Worker rotation between tasks - reducing daily exposures over the course of a shift.

  • Application of work permits - identifying minimum requirements prior to work commencement.

  • Provision of information, instruction and training - internal or external training provisions could be considered to boost worker knowledge on control systems and their applications.

  • Implementation of safety signage.

Do You Need Support with COSHH?

It is hoped that this article goes some way to providing a brief overview of COSHH. If you wish to know more on this subject or need support with your COSHH assessments, exposure monitoring or the testing of your LEV systems, RPE Fit Testing then please feel free to get in touch with us through social media or our website (, by email at or simply give us a call on 01709 931299.

Visit our Services Page Here:

89 views0 comments


bottom of page