After an asbestos removal project you need to ensure your site is safe to occupy. U.K. law dictates that following a licensed asbestos removal project a four stage clearance needs to be completed. An independent company (i.e. not the asbestos removal contractor) needs to complete this assessment.

The completion of the four stage clearance is an important part of the removals process. It protects from asbestos and enables you to meet your legal duties. You need to ensure that you engage the right company.

You should also check if an analytical company uses subcontractors. If they do, the checks outlined below will need to be completed for them too.

Asbestos consultant in PPE

UKAS Accreditation ISO 17025: 2017

The Control of Asbestos Regulations 2012 dictates that only UKAS accredited companies can complete fibre counting and four stage clearances.

To achieve UKAS accreditation an analytical company will have to successfully demonstrate:

  • Effective methods of analysis and inspection.
  • Comprehensive policies and procedures. These need to be in place for everything from technical processes through to a privacy policy.
  • Suitable documentation, data processing and storage.
  • Effective, transparent, impartial quotation processes.
  • Effective complaint and feedback mechanisms.
  • Robust training systems and records.
  • Employee audit programmes.

Request a copy of the laboratory’s UKAS certificate and up to date accreditation schedule.


To secure UKAS accreditation, laboratories need to show that their employees are competent:

British Occupational Hygiene Society (BOHS) Certificate of Competence in Asbestos (CoCa) S301

Accreditation requires at least one senior member of the laboratory’s team to hold CoCa. This BOHS certificate is gained through two examinations:

  • One written - S301 ‘Asbestos and other fibres’.
  • One oral - to sit this test, candidates must have passed the written exam and gained at least six months practical experience. Prior to completing this second test, candidates have to submit a written report on a suitable asbestos subject.

BOHS P403 and P404

BOHS has developed a range of five proficiency modules. These train people in specific areas of asbestos work. Out of these five modules, P403 and P404 apply to air testing and four stage clearance work:

  • P403 - asbestos fibre counting
  • P404 - air sampling and clearance testing of asbestos

UKAS accreditation requires all analysts completing air tests and clearances to hold these P modules or the S301 exam.

Each module is a stand alone training course. They run over 2-3 days and cover both theory and practical training. The aim is to help individuals become proficient in that area of work. Both of the modules have practical assessments and written examination. 

You should request copies of training certificates for your site file.

Regular Interlaboratory Counting Exchange (RICE)

RICE assesses the proficiency of laboratories counting asbestos fibres in air. The RICE scheme is operated by the Health and Safety Executive (HSE). Their testing and monitoring department oversees its management, registration and membership. They organise and distribute samples to count to the participants. They also then process the count data submitted.

Counts submitted are compared with reference values for each slide. They are then catagorised as A, B or C. After four rounds have been completed, if 75% or more of the counts are in the catagories A or B the laboratory is classified as ‘satisfactory’.

Participation in the scheme is recommended in the HSE’s Guidance - HSG 248 “Asbestos: The analyst’s guide for sampling, analysis and clearance procedures.” It is also a prerequisite for accreditation of this analysis to ISO 17025: 2017.

You should request a copy of their most up to date RICE certificate for your site file.


You need to check that an analytical company has suitable insurance in place to cover your project. They need to have public liability, professional indemnity and employers liability policies. You also need to check that their limits of indemnities are suitable. Request a copy of their insurance certificates for your records.

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