COSHH – Fundamentals of Risk Assessment and Control P304

Hazardous substances are used every day in the workplace. They include anything from office cleaning products to specialist chemicals used in manufacturing, and can also be generated from processes such as welding and fuel combustion. Exposure to hazardous substances via inhalation, skin contact or ingestion can result in short- and long-term health effects for workers, which in some cases can be fatal.  

The Control of Substances Hazardous to Health (COSHH) Regulations 2002 place a duty on employers to protect their workers from exposure to hazardous substances. It is the responsibility of the employer to either carry out or appoint a competent person to carry out a full workplace risk assessment, which identifies appropriate workplace controls and other measures designed to minimise risks. Furthermore, the employer is required to implement the control measures identified in the risk assessment before commencing work that is liable to expose employees to any relevant hazardous substances.  

Who is it for?

P304 - Assessments under the COSHH Regulations gives you the requisite knowledge to conduct risk assessments in line with the COSHH Regulations. The qualification teaches you how to identify hazardous substances in a work environment, and how to control them effectively, to a standard which prevents or reduces risks of occupational ill-health. 

This qualification is suitable for anyone responsible for worker health. This includes:  

  • Occupational hygienists 
  • Health and safety practitioners 
  • Managers and other duty-holders under COSHH 


The level of a qualification indicates the relative complexity and depth of knowledge and skills required to attain the qualification.  

This is a level 4 qualification in the BOHS qualifications framework. 

How is it delivered?

P304 runs typically over three consecutive days and requires approximately 24 hours of study time. This is split down into: 

  • 18 hours of teaching time (including formative practical assessment) 
  • 6 hours of independent study (including pre-reading and evening study)  

The course can be delivered more flexibly, such as one day per week for three weeks, but should still include 24 hours of study time. 

Modules / Learning objectives 

Overall objectives 

To give you practical guidance on assessing the health risks caused by hazardous substances, to meet the requirements of the Control of Substances Hazardous to Health (COSHH) Regulations 2002 for a 'suitable and sufficient' risk assessment. 


  1. Introduction to hazard and risk 
  2. Legal aspects 
  3. Fundamental principles of risk assessments 
  4. Making a risk assessment 
  5. Workplace controls 


You must pass two assessments:  

  • Formative practical assessment
  • Written examination 


BOHS provides: 

  • Further information can be found in the course specification, under the ‘Downloadable Resources’ information box above.
  • BOHS Online Exam information and FAQs - Click here 
  • Examination Guidance for tutors which provides sample examination questions and guidance on the written examinations, under the ‘Downloadable Resources’ information box above.

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