Scanning Electron Microscopy Fibre Counting Scheme
SEMS QC Samples Available Upon Request - Subject to
Please contact the PT Team
for further information
SEMS R9 Samples Will Be
Results Deadline Date
Proficiency Testing Scheme Overview
Our SEM Fibre Counting Scheme (SEMS) aims to assess the
proficiency of laboratories counting asbestos fibres in air using
Scanning Electron Microscopy. The SEM scheme is operated by HSL in
association with APC, Germany and TNO, Netherlands. HSL oversees
the management, registration, and membership matters together with
distribution of the samples and processing the laboratory data.
Analytes in the Scheme
Asbestos and other inorganic fibres are mounted on gold coated
Who Should Participate?
Control of Asbestos Regulations require laboratories that
undertake this type of analysis be accredited by the United Kingdom
Accreditation Service (UKAS) to
ISO 17025. The arrangments in other countries may be different.
Any laboratory that is accredited to the ISO 17025 standard for
this type of analysis is likely to be required to participate in an
appropriate PT Scheme by their national accreditation body.
What are the Recommended Methods?
The recommended methods of analysis are the
ISO 14966 (2002) and the VDI 3492 (2014).
The participant handbook provides a comprehensive overview
of the operation of the SEM PT scheme and can be found under
Operation of the Scheme
There is one sample distribution per year, with samples normally
dispatched in October. Each Round will comprise four samples
representing a range of asbestos and other inorganic fibres at
concentration ranges typically between 10-150 fibres per
mm2. The samples are intended to be analysed once only
and may be retained by the laboratory after the analysis has been
completed. Participants will normally have approximately 25 working
days to analyse the samples and report the results. Upon submission
of results participants receive a Group Summary Report. Initially
participating laboratories will be given feedback on their
performance but will not be formally scored. Performance criteria
and a final classification will be produced as the scheme
- Samples are distributed by an approved hazardous materials
- The Group Summary Report will be sent within one month of
completion of each round.
Address & Phone Number
The Proficiency Testing Team
Health and Safety Laboratory
Tel: +44 (0) 203 028 3382
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