Air Sampling and Fibre Counting (PCM) P403

Analysis of airborne samples plays a key role when managing asbestos in buildings in line with the Control of Asbestos Regulations (CAR) 2012. P403 – Air Sampling and Fibre Counting (PCM) gives analysts the knowledge and skills required to safely take air samples, prepare fibre counting slides, and accurately analyse these slides under a microscope to identify airborne fibre levels within the building or site. 

Who is it for?

The qualification is suitable for anyone who is:  

  • Required to undertake air sampling and fibre counting as part of their work 
  • Considering a career in asbestos analysis 
  • Responsible for managing asbestos analysts 


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, equivalent to NVQ Level 4 (HNC). 

How is it delivered?

The P403 course will require at least 18 hours of study time, of which 14 hours will be taught (teaching and practical assessments) and 4 hours will be independent (in your own time).  In addition there will be 6 hours of examination time.


Content / Learning outcomes

Overall aim

To provide you with the theoretical knowledge and practical ability to undertake air sampling in relation to asbestos and fibre counting to quantify respirable fibres using phase contrast microscopy (PCM).

Learning outcomes

On completion of this module, you will be able to demonstrate the correct method for:

  • Setting up air sampling equipment and collecting air samples
  • Mounting and clarifying the filter on a microscope slide
  • Setting up the microscope and required quality checks
  • Analysing samples and providing accurate fibre counts


  1. Air sampling equipment, sampling strategies and collection of samples
  2. Sample preparation and setting up of microscope
  3. Fibre counting and calculation of results
  4. Certificates and reporting results
  5. Quality control


You must pass three parts within 12 months:  

  • Practical assessment 
  • Written examination
  • Practical examination 


BOHS provides: 

  • Further information about the practical assessment and examinations plus sample examination questions

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