Guidance on COSHH Risk Assessment

COSHH stands for the Control of Substances Hazardous to Health, first introduced in 1988 by the Health and Safety Executive (HSE). Aiming to reduce accidents and minimise the risk to employee health in the workplace, COSHH was introduced to ensure any business using hazardous substances does so in a controlled and safe way.

30 years on, however, the guidance is still misunderstood so Martyn Deacon, SOCOTEC’s technical manager for Occupational Hygiene, is offering further support to help others interpret and understand the COSHH risk assessment. 

Some effects of hazardous substances include:

  • Lung damage - Chronic Obstructive Pulmonary Disease (COPD) / Occupational asthma, as a result of inhalation of substances used at work;
  • Skin irritation or dermatitis as a result of skin contact;
  • Losing consciousness as a result of being overcome by toxic fumes;
  • Cancer, which may appear long after the exposure to the chemical that caused it;
  • Infection from bacteria and other micro-organisms (biological agents).

It’s important that all businesses, and even those individuals who are self-employed, take the necessary steps to protect themselves. COSHH applies to all industries using harmful substances including: catering, baking, beauty and hairdressing, cleaning, agriculture, quarries, engineering, manufacturing, motor vehicle repair etc.

Besides substances for which a Safety Data Sheet (SDS) is provided, processes that generate harmful substances must also be considered e.g. Respirable Crystalline Silica (RCS) from stone works; Diesel Engine Exhaust Emissions (DEEEs) from vehicles and generators; welding fume, woodworking dust, etc.

Why is COSHH Important?

The purpose of COSHH is to protect the well-being of employees, which is required by law.

It guides you through evaluating the risks in your business and how you can best control or prevent them. Health monitoring, assessment of procedures and equipment should be undertaken regularly to ensure you uphold your compliance with COSHH. Most businesses will work with some substances which pose a risk to health; even exposures to general dusts - or products such as mild cleaning agents can be hazardous to employees if not used correctly.

A Recent Change in Control Standards

The HSE has recently announced some important news, on raised control standards for welding fumes. On 14 January 2019, the HSE shared with the Industry and Regulatory Forum on LEV that they have raised enforced control measures for welding operations in the UK.

This follows an announcement from the International Agency for Research on Cancer (IARC), who classified welding fumes and UV radiation from welding as Group 1 carcinogens. IARC published their findings in Lancet Oncology in 2017 in a paper titled ‘Carcinogenicity of welding, molybdenum trioxide, and indium tin oxide’.

The raised enforced control standards are detailed below:

  • All forms of welding fume can cause cancer
  • Control is required
  • Indoor welding tasks require the use of LEV. If LEV is unable to control fume capture then Respiratory Protective Equipment (RPE) is also required
  • Outdoor welding requires use of RPE
  • Enforcement of the raised control standards is with immediate effect under COSHH Regulation 7

Your control measures will depend entirely on the hazard itself. Adequate control under COSHH means:

  • Apply the 8 principles of COSHH
  • Do not exceed the WEL
  • If the substance causes cancer, heritable damage or asthma, reduce exposure to as low as reasonably possible.

HSE provide details on adequate control including how to use, store, label and dispose of dangerous substances.

The 8 steps you can take to ensure you are compliant with COSHH are:

  • Step 1. COSHH Risk Assessment; the risk assessment will identify all harmful substances which can damage health and the tasks where there is exposure to these materials.
  • Step 2. Precautions; if you identify risks from your initial assessment, you should review precautions you can take to remove the risk or whether it’s possible to change internal processes.
  • Step 3. Prevention or Adequate Control of Exposure; if you can’t eliminate the risk, control measures should be put in place for each risk based activity you identified in your assessment.
  • Step 4. Maintenance of Control Measures; COSHH requires that you maintain your controls so they perform to the same standard as when they were initially introduced.
  • Step 5. Monitoring exposure; to comply with COSHH, you may need to measure the concentration of hazardous substances in the air which could be breathed in by workers, where your risk assessment has concluded that exposure limits may be surpassed, control measures aren’t working properly or there is a serious risk to health if control measures fail.
  • Step 6. Health Surveillance; after taking the steps outlined above, it will be apparent where some risk remains. Where appropriate, health surveillance should be a regularly planned assessment and health records need to be kept for at least 40 years.
  • Step 7. Creating Plans and Procedures; in the event of an accident or emergency, you need to have the necessary processes in place to handle such a situation.  This involves planning for an emergency whereby the exposure to dangerous substances goes far beyond day to day contact
  • Step 8. COSHH Training; all employees need to be properly trained and provided with the relevant instructions.


Download our 8-Step Guide to be COSHH Compliant.


SOCOTEC’s qualified occupational hygienists can provide a full service from hazard identification and monitoring to quantifying exposure and recommendations to improve exposure controls, as well as assistance with the COSHH assessment process.


For more information, get in touch.


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