NIST HANDBOOK 150-3 

2006 Edition 

National 

Voluntary

Laboratory 

Accreditation 

Program 

BULK

ASBESTOS

ANALYSIS

Hazel M. Richmond 

National Voluntary Laboratory Accreditation Program 

Standards Services Division 

Technology Services 

July 2006 

U.S. Department of Commerce 

Carlos M. Gutierrez, Secretary 

National Institute of Standards and Technology 

William A. Jeffrey, Director 
NVLAP AND THE NVLAP LOGO 

The term NVLAP and the NVLAP logo are registered 

marks of the Federal Government, which retains 

exclusive rights to control the use thereof. Permission 

to use the term and symbol (NVLAP logo with 

approved caption) is granted to NVLAP-accredited 

laboratories for the limited purpose of announcing 

their accredited status, and for use on reports that 

describe only testing and calibration within the scope 

of accreditation. NVLAP reserves the right to control 

the quality of the use of the NVLAP term, logo, and 

symbol.
Contents 

Contents .......................................................................................................................................................iii

Foreword.......................................................................................................................................................v

Introduction..................................................................................................................................................vi

1 General information ..............................................................................................................................1

1.1 Scope ...........................................................................................................................................1

1.2 Organization of handbook ...........................................................................................................1

1.3 Program description.....................................................................................................................1

1.4 References ...................................................................................................................................1

1.5 Terms and definitions ..................................................................................................................2

1.6 Program documentation...............................................................................................................5

2 LAP establishment, development and implementation.........................................................................6

3 Accreditation process............................................................................................................................6

3.1 General ........................................................................................................................................6

3.2 Management system review ........................................................................................................6

3.3 On-site assessment.......................................................................................................................6

3.4 Proficiency testing .......................................................................................................................7

4 Management requirements for accreditation.........................................................................................9

4.1 Organization ................................................................................................................................9

4.2 Management system ....................................................................................................................9

4.3 Document control ........................................................................................................................9

4.4 Review of requests, tenders and contracts...................................................................................9

4.5 Subcontracting of tests and calibrations ......................................................................................9

4.6 Purchasing services and supplies...............................................................................................10

4.7 Service to the customer..............................................................................................................10

4.8 Complaints.................................................................................................................................10

4.9 Control of nonconforming testing and/or calibration work.......................................................10

4.10 Improvement..............................................................................................................................10

4.11 Corrective action .......................................................................................................................10

4.12 Preventive action .......................................................................................................................10

4.13 Control of records......................................................................................................................10

4.14 Internal audits ............................................................................................................................11

4.15 Management reviews.................................................................................................................11

5 Technical requirements for accreditation............................................................................................11

5.1 General ......................................................................................................................................11

5.2 Personnel ...................................................................................................................................11

5.3 Accommodation and environmental conditions ........................................................................12

5.4 Test and calibration methods and method validation ................................................................12

5.5 Equipment..................................................................................................................................14

5.6 Measurement traceability ..........................................................................................................15

5.7 Sampling....................................................................................................................................16

NIST Handbook 150-3:2006 iii 
5.8 Handling of test and calibration items.......................................................................................16

5.9 Assuring the quality of test and calibration results....................................................................17

5.10 Reporting the results..................................................................................................................17

6 Additional requirements......................................................................................................................18

Annex A (normative) Documents required in the laboratory .....................................................................19

iv NIST Handbook 150-3:2006 
Foreword 

The NIST Handbook 150 publication series sets forth the procedures, requirements, and guidance for the 

accreditation of testing and calibration laboratories by the National Voluntary Laboratory Accreditation 

Program (NVLAP). The series is comprised of the following publications: 

• NIST Handbook 150, NVLAP Procedures and General Requirements, which contains the general 

procedures and requirements under which NVLAP operates as an unbiased third-party accreditation 

body; 

• NIST Handbook 150-xx program-specific handbooks, which supplement NIST Handbook 150 by 

providing additional requirements, guidance, and interpretive information applicable to specific 

NVLAP laboratory accreditation programs (LAPs). 

The program-specific handbooks are not stand-alone documents, but rather are companion documents to 

NIST Handbook 150. They tailor the general criteria found in NIST Handbook 150 to the specific tests, 

calibrations, or types of tests or calibrations covered by a LAP. 

NIST Handbook 150-3, NVLAP Bulk Asbestos Analysis, presents the technical requirements and guidance 

for the accreditation of laboratories under the NVLAP Bulk Asbestos Analysis LAP. The 2006 edition 

incorporates changes resulting from the release of the newest editions of ISO/IEC 17025, General 

requirements for the competence of testing and calibration laboratories, and NIST Handbook 150, as 

well as editorial improvements. The 2006 edition of NIST Handbook 150-3 supersedes and replaces the 

1994 edition. 

The handbook was revised with the participation of technical experts in the field of bulk asbestos testing 

and was approved by NVLAP. The following main changes have been made to this handbook with 

respect to the previous edition: 

• all references to applicable international guides and standards have been updated; 

• Laboratory Bulletins (LB-2-1998 and LB-3-1999), previously issued for clarification, have been 

incorporated into this edition of the handbook; 

• on-site assessment checklists and the test method selection list are no longer included in order that 

they may be provided as separate documents, which may be updated at different intervals than the 

handbook; 

• the body of the handbook has been restructured to conform with internationally accepted rules for the 

structure and drafting of standards, where appropriate, to promote ease of use and understanding; 

• Annex A, Documents required in the laboratory, has been added. 

This handbook is also available on the NVLAP web site (http://www.nist.gov/nvlap). 

Questions or comments concerning this handbook should be submitted to NVLAP, National Institute of 

Standards and Technology, 100 Bureau Drive, Stop 2140, Gaithersburg, MD, 20899-2140; phone: 

301-975-4016; fax: 301-926-2884; e-mail: nvlap@nist.gov. 

NIST Handbook 150-3:2006 v 
Introduction 

The Asbestos Hazard Emergency Response Act (AHERA) was enacted in October 1986. AHERA 

requires laboratories that analyze asbestos bulk insulation samples taken from public, or private, 

elementary or secondary schools, to be accredited by the National Institute of Standards and Technology 

(formerly the National Bureau of Standards) National Voluntary Laboratory Accreditation Program 

(NVLAP). NVLAP accredits laboratories for the 1982 procedure, Interim Method for the Determination 

of Asbestos in Bulk Insulation Samples, found in 40 CFR Part 763, Appendix E to Subpart E (formerly 

Appendix A to Subpart F). AHERA requires that two types of asbestos analysis laboratories be 

accredited by NVLAP: those performing analysis using polarized light microscopy (PLM) and those 

performing analysis using transmission electron microscopy (TEM). 

To meet the need for an accrediting mechanism in the period before the implementation of the 

NIST/NVLAP Program, the U. S. Environmental Protection Agency (EPA) Bulk Sample Analysis 

Quality Assurance Program was continued as the Interim Asbestos Bulk Sample Analysis Quality 

Assurance Program. This program provided a source of accredited laboratories until NVLAP-accredited 

laboratories were available. PLM laboratories accredited in the April 1988 round of testing received EPA 

interim accreditation until January 12, 1989. However, NVLAP did not begin to accredit laboratories 

until April 1989. To provide a source of accredited laboratories after January 12, 1989, EPA developed a 

process for extending interim accreditation. Under this process, a laboratory received an extension if it 

had fully applied to NVLAP by September 30, 1988, and NVLAP had not yet completed its evaluation. 

EPA interim accreditation was revoked, however, if the laboratory failed NVLAP proficiency testing 

and/or the on-site assessment. 

All extensions granted by EPA expired on October 30, 1989. After this date, PLM laboratories analyzing 

bulk samples taken from public, or private, elementary or secondary schools, were required to be 

accredited by NVLAP. 

In 1993, the EPA developed an improved method entitled Method for the Determination of Asbestos in 

Bulk Building Materials, EPA/600/R-93/116. The test method provides clarifications and improvements 

to the 1982 method and is recommended for use as the preferred substitute method. Use of the improved 

method can provide more precise analytical results at low asbestos concentrations, enhanced analysis of 

floor tiles that may contain thin asbestos fibers below the limits of resolution of the PLM, and clearer 

instruction on the analysis of bulk materials, particularly where multiple layers are present. While the 

improved method is recommended by the EPA to be used in place of the 1982 procedure, and serve as the 

preferred substitute method, it has not been designated as the new interim method. NVLAP laboratories 

that use the EPA/600/R-93/116 method must indicate it on their test reports. 

The technical content of this handbook was originally developed by the Surface and Microanalysis 

Science Division of the National Institute of Standards and Technology and was updated in 1994 to 

reflect new requirements and information. 

For this edition of the handbook, special thanks for their contributions go to NVLAP assessors Peter 

Cooke, Steve Lerman, Thomas Emma, Charles Knowles, Wade Mullin, Larry Pierce, Shu-Chun Su, and 

Gerald Wright. 

vi NIST Handbook 150-3:2006 
1 General information 

1.1 Scope 

1.1.1 This handbook specifies the technical requirements and provides guidance for the accreditation of 

laboratories under the NVLAP Bulk Asbestos Analysis Program (PLM Program). It supplements the 

NVLAP procedures and general requirements found in NIST Handbook 150, by tailoring the general 

criteria found in NIST Handbook 150 to the specific tests covered by the PLM Program. 

1.1.2 NIST Handbook 150, this handbook, and their respective checklists (see 1.6) constitute the 

collective body of requirements that must be met by a laboratory seeking NVLAP accreditation for the 

PLM Program. These requirements include satisfactory performance in selected proficiency testing, as 

required, and fulfilling the on-site assessment requirements, including resolution of identified 

nonconformities. 

1.1.3 This handbook is intended for information and use by accredited PLM laboratories, assessors 

conducting on-site assessments, laboratories seeking accreditation, other laboratory accreditation systems, 

users of laboratory services, and others needing information on the accreditation requirements under the 

PLM Program. 

1.1.4 Any laboratory (including commercial, manufacturer, university, or federal, state, or local 

government laboratory) that performs the PLM test method may apply for NVLAP accreditation.

1.2 Organization of handbook 

The numbering and titles of the first five clauses of this handbook match those of NIST Handbook 150. 

The primary subclauses in clauses 4 and 5 (e.g., 4.1, 4.2, etc.) are also numbered and titled to correspond 

with those of NIST Handbook 150, even when there are no requirements additional to those in NIST 

Handbook 150. 

Annex A provides a list of documents that are required to be available in a laboratory accredited under the 

PLM Program. 

1.3 Program description 

The purpose of the PLM Program is to accredit testing laboratories to provide assurance that they are 

competent to analyze bulk samples for asbestos using polarized light microscopy (PLM). Public Law 

99-519, Asbestos Hazard Emergency Response Act of 1986, referred to as AHERA, requires the National 

Institute of Standards and Technology (formerly the National Bureau of Standards) to develop an 

accreditation program for laboratories conducting analyses of bulk samples of asbestos-containing 

materials. 

1.4 References 

The following documents are referenced in this handbook. For dated references, only the edition cited 

applies. For undated references, the latest edition of the referenced document (including any 

NIST Handbook 150-3:2006 1 
amendments) shall apply within one year of publication or within another time limit specified by 

regulations or other requirement documents. 

— NIST Handbook 150, NVLAP Procedures and General Requirements 

— U.S. Environmental Protection Agency Interim Method for the Determination of Asbestos in Bulk 

Insulation Samples as found in 40 CFR, Part 763, Subpart E, Appendix E (formerly Subpart F, 

Appendix A), EPA/600/M4-82-020, 1982, or the current U.S. Environmental Protection Agency 

method for the analysis of asbestos in building material 

— U.S. Environmental Protection Agency Method for the Determination of Asbestos in Bulk Building 

Materials (EPA/600/R-93/116), 1993, R. L. Perkins and B. W. Harvey 

— NISTIR 5951, Guide for the Quality Control on the Qualitative and Quantitative Analysis of Bulk 

Asbestos Samples: Version 1, Jennifer R. Verkouteren and David L. Duewer 

— Guide to Statistical Analysis of Bulk Asbestos Quality Control Data, Steve Lerman (available from 

NVLAP upon request) 

1.5 Terms and definitions 

For the purposes of this handbook, the terms and definitions given in NIST Handbook 150 apply and the 

following apply: 

1.5.1 

asbestos

A commercial term applied to the asbestiform varieties of six different minerals. The asbestos types are 

chrysotile (asbestiform serpentine), amosite (asbestiform grunerite), crocidolite (asbestiform riebeckite), 

asbestiform anthophyllite, asbestiform tremolite, and asbestiform actinolite. The properties of asbestos 

that caused it to be widely used commercially are: 1) its ability to be separated into long, thin, flexible 

fibers; 2) high tensile strength; 3) low thermal and electrical conductivity; 4) high mechanical and 

chemical durability; and 5) high heat resistance. 

1.5.2 

Becke line 

A band of light seen at the periphery of a specimen when the refractive indices of the specimen and the 

mounting medium are different; it is used to determine refractive index. 

1.5.3 

bias 

A systematic error characterized by a consistent (non-random) measurement error. 

1.5.4 

binder 

With reference to a bulk sample, a component added for cohesiveness (e.g., plaster, cement, glue, etc.). 

2 NIST Handbook 150-3:2006 
1.5.5 

birefringence 

The numerical difference between the maximum and minimum refractive indices of an anisotropic 

substance. Birefringence may be estimated using a Michel-Levy chart from the interference colors 

observed under crossed polars. Interference colors are also dependent on the orientation and thickness of 

the grain, and therefore are used qualitatively to determine placement in one of the four categories listed 

below. 

 Qualitative Quantitative (N-n)

none 0.00 or isotropic 

low ≤ 0.010 

moderate 0.011-0.050 

 high > 0.050 

1.5.6 

bulk sample 

A sample of building material taken for the identification and quantification of asbestos. Bulk building 

materials may include a wide variety of friable and non-friable materials. 

1.5.7 

color 

The color of a particle or fiber when observed under low-power magnification using top-lighting. 

1.5.8 

compensator 

A device with known, fixed or variable retardation and vibration direction used for determining the 

degree of retardation (hence the thickness or value of birefringence) in an anisotropic specimen. It is also 

used to determine the sign of elongation of elongated materials. The most common compensator is the 

first-order red plate (530 nm to 550 nm retardation). 

1.5.9 

control chart 

A graphical plot of test results with respect to time or sequence of measurement, together with limits 

within which they are expected to lie when the system is in a state of statistical control. 

1.5.10 

detection limit 

The smallest concentration/amount of some component of interest that can be measured by a single 

measurement with a stated level of confidence. 

1.5.11 

dispersion staining (focal masking) 

An optical means of imparting apparent or virtual color to transparent substances by the use of an opaque 

screen (stop) in the objective back focal plane; it is used to determine refractive indices. 

1.5.12 

extinction 

The condition in which an anisotropic substance appears dark when observed between crossed polars. 

This occurs when the vibration directions in the specimen are parallel to the vibration directions in the 

polarizer and analyzer. Extinction may be complete or incomplete; common types include parallel, 

oblique (inclined), symmetrical and undulose. 

NIST Handbook 150-3:2006 3 
1.5.13 

extinction angle 

For fibers, the angle between the extinction position and the position at which the fiber is parallel to the 

polarizer or analyzer privileged directions. 

1.5.14 

fiber 

With reference to asbestiform morphology: a structure consisting of one or more fibrils. 

1.5.15 

friable 

Refers to the cohesiveness of a bulk material, indicating that it may be crumbled or disaggregated by hand 

pressure. 

1.5.16 

gravimetry 

Any technique in which the concentration of a component is determined by weighing. As used in this 

document, it refers to the measurement of asbestos-containing residues after sample treatment by ashing, 

dissolution, etc. 

1.5.17 

homogeneous 

Uniform in composition and distribution of all components of a material, such that multiple subsamples 

taken for analysis will contain the same components in approximately the same relative concentrations. 

1.5.18 

matrix 

Nonasbestos, nonbinder components of a bulk material; for example, such components as cellulose, 

fiberglass, mineral wool, mica, etc. 

1.5.19 

Michel-Levy scale of retardation colors 

A chart plotting the relationship between birefringence, retardation and thickness of anisotropic 

substances. Any one of the three variables can be determined if the other two are known. 

1.5.20 

morphology 

The structure and shape of a particle. Characterization may be descriptive (platy, rod-like, acicular, etc.) 

or in terms of dimensions such as length and diameter (see asbestiform). 

1.5.21 

oblique illumination 

Illumination by light that is at an oblique angle to the optical axis. 

1.5.22 

pleochroism 

The change in color or hue of a colored anisotropic substance when rotated relative to the vibration 

direction of plane polarized light. 

4 NIST Handbook 150-3:2006 
1.5.23 

point counting 

A technique used to determine the relative projected areas occupied by separate components in a 

microscope slide preparation of a sample. For asbestos analysis, this technique is used to determine the 

relative concentrations of asbestos minerals to nonasbestos sample components. 

1.5.24 

refractive index (index of refraction) 

The ratio of the velocity of light in a vacuum relative to the velocity of light in a medium. It is expressed 

as n and varies with wavelength and temperature. 

1.5.25 

sign of elongation 

Referring to the location of the high and low refractive indices in an elongated anisotropic substance, a 

specimen is described as positive when the higher refractive index is lengthwise (length slow), and as 

negative when the lower refractive index is lengthwise (length fast). 

1.5.26 

trace 

The quantity of asbestos that is above the laboratory’s detection limit and below its limit of quantification. 

1.5.27 

visual estimation 

An estimation of the concentration of asbestos in a sample as compared to other sample components. 

1.6 Program documentation 

1.6.1 General

Assessors use NVLAP checklists to ensure that each laboratory receives an assessment comparable to that 

received by others. Checklists assist assessors in documenting the assessment to the NVLAP 

requirements found in NIST Handbook 150, this handbook, and the checklists themselves. Checklists 

contain definitive statements or questions about all aspects of the NVLAP criteria for accreditation, and 

form part of the On-Site Assessment Report (see NIST Handbook 150). The current version of each 

checklist is available on the NVLAP web site <http://www.nist.gov/nvlap>. 

1.6.2 NIST Handbook 150 Checklist 

All NVLAP programs use the NIST Handbook 150 Checklist (formerly called the General Operations 

Checklist), which contains the requirements published in NIST Handbook 150. The checklist items are 

numbered to correspond to clauses 4 and 5 and annexes A and B of NIST Handbook 150. 

1.6.3 NIST Handbook 150-3 Checklist 

The NIST Handbook 150-3 Checklist (also referred to as the Bulk Asbestos Program-Specific Checklist) 

addresses the requirements specific to bulk asbestos analysis testing given in NIST Handbook 150-3. The 

checklist may contain requirements expressed at a more detailed level than found in this handbook. 

NIST Handbook 150-3:2006 5 
1.6.4 NVLAP Lab Bulletins 

NVLAP Lab Bulletins are issued to laboratories and assessors, when needed, to clarify program-specific 

requirements and to provide information about program additions and changes. 

2 LAP establishment, development and implementation 

This clause contains no information additional to that provided in NIST Handbook 150, clause 2. 

3 Accreditation process 

3.1 General 

An overview of the laboratory accreditation process is provided in NIST Handbook 150, clause 3, and 

includes information pertaining to application for accreditation; on-site assessment; proficiency testing; 

accreditation decision; granting accreditation; renewal of accreditation; changes to scope of accreditation; 

monitoring visits; and suspension, denial, revocation, and voluntary termination of accreditation. 

3.2 Management system review 

3.2.1 Prior to applying to NVLAP for accreditation, a laboratory shall have a fully implemented 

management system. 

3.2.2 The NVLAP assessor assigned to conduct the on-site assessment will request a copy of the 

laboratory’s management system manual and relevant documented procedures in advance of the 

assessment to reduce time at the laboratory. 

3.2.3 The assessor will review all relevant management system documentation for conformity with 

NVLAP requirements, including the requirements of NIST Handbook 150 and this handbook. During 

this review, the assessor may request additional management system documents and/or records, which 

will be returned upon request. 

3.3 On-site assessment 

3.3.1 The purpose of the on-site assessment is to determine if the laboratory is following its 

documented management system and to assess the competence of the laboratory’s delivery of its testing 

services. The laboratory shall be prepared for conducting test demonstrations, have equipment in good 

working order, and be ready for examination according to the requirements identified in this handbook, 

NIST Handbook 150, and the laboratory’s management system manual. The assessor will need time and 

workspace to complete assessment documentation while at the laboratory. 

3.3.2 An opening meeting is conducted with the laboratory manager to explain the purpose of the onsite visit and to discuss the schedule for the day(s). At the discretion of the laboratory manager, other 

staff may attend the meeting. 

6 NIST Handbook 150-3:2006 
3.3.3 At least one staff member shall be available to answer questions; however, the assessor may wish 

to review the documents and records alone. The assessor usually does not ask to remove any laboratory 

documents or records from the laboratory premises. 

3.3.4 The results of proficiency testing shall be made available to the on-site assessor for use during the 

on-site assessment. 

3.3.5 The assessor physically examines equipment and facilities, and observes and interviews personnel 

who demonstrate selected procedures. The demonstrations requested may be selective or all-inclusive, 

and shall include sample test material(s), preparation devices, establishment of test conditions and the 

setup/use of major equipment. The assessor may provide a proficiency test sample and request a specific 

demonstration. 

3.3.6 The assessor completes an On-Site Assessment Report, which clearly lists all nonconformities 

and comments (both positive and negative). 

3.3.7 The assessor conducts a closing meeting, attended by appropriate laboratory personnel, to discuss 

the findings, including comments and nonconformities. The first page of the report shall be signed by the 

assessor and the laboratory’s Authorized Representative to acknowledge the discussion, but does not 

necessarily indicate agreement; appeals may be made through NVLAP. 

3.3.8 The information obtained by the assessor is held in the strictest confidence. 

3.4 Proficiency testing 

3.4.1 NIST Handbook 150 defines proficiency testing and describes how it is included in the 

accreditation process.

3.4.2 Proficiency testing is required for all laboratories before initial accreditation can be granted and 

for maintaining accreditation in the bulk asbestos program. 

3.4.3 The proficiency testing materials, in general, are representative examples of bulk insulation 

materials or their derivatives. The goal of the program is to provide material that will test the laboratory’s 

ability to follow the test method and to achieve the proper accuracy, precision, and detection limits. 

3.4.4 The proficiency test contractor will send participating laboratories test samples, data sheets, and 

instructions for performing the test and reporting the results. The test shall be conducted in accordance 

with EPA/600/M4-82-020, 1982, or the current U.S. Environmental Protection Agency method for the 

analysis of asbestos in building material, using the laboratory’s normal operating procedures. 

3.4.5 Proficiency testing shall not be contracted out to another laboratory. 

NOTE A laboratory that subcontracts proficiency testing to another laboratory will be immediately suspended for 

not participating in the test round and risks revocation of its accreditation. (See also 3.4.13.)

3.4.6 Special instructions shall also be followed as they are designed to ensure uniformity in procedures 

among participants. Completed data sheets shall be returned to NVLAP or its designated contractor for 

analysis by the date specified on the data sheets. Failure to return the proficiency testing data sheets by 

the deadline date will result in penalties, which may include failing that round (see 3.4.11). 

NIST Handbook 150-3:2006 7 
3.4.7 Proficiency testing may involve materials or artifacts that shall be returned to NVLAP for use by 

other participants. These materials shall be protected from damage both in the laboratory and during 

shipment back to NVLAP, or its designated contractor. Examples of such materials and artifacts are: 

permanently mounted slides, photographs, glasses, and special optical materials. These materials may be 

used to determine testing performance for specific subparts of the test method. Unless otherwise noted, 

laboratories should use proficiency test materials for in-house instructional materials. 

3.4.8 Occasionally, laboratories may be sent blind samples to test their proficiency under normal 

conditions. The results of any blind testing will be used to determine a laboratory’s continued compliance 

with NVLAP requirements. 

3.4.9 All analysts, including those in sub-facilities, shall participate in proficiency testing. Each analyst 

shall separately analyze, record, and report test results. The laboratory shall report one result to NVLAP. 

The test results shall be used for inter-analyst comparisons and entered into the management system 

records. 

3.4.10 NVLAP will report proficiency test performance to participants in appropriate documents. The 

identity and performance of individual laboratories will remain confidential. Any problems indicated by 

proficiency testing shall be discussed with appropriate laboratory personnel, who shall then be responsible 

for developing and implementing plans for resolution. The satisfactory resolution of proficiency testing 

nonconformities is required. 

3.4.11 If an accredited laboratory fails a round of proficiency testing, it shall do the following to 

maintain its accreditation: 

a) provide to NVLAP within 30 days of notification of the failure, detailed, written documentation 

that includes an analysis of why the laboratory failed, and what corrective action(s) it has taken 

(analyst training, revised procedures, quality assurance activities, etc.) to resolve its analytical 

problem(s) to avoid similar errors in the future; 

b) provide documentation to show that the corrective action(s) has been effectively implemented; 

c) pass the next round of proficiency testing. 

3.4.12 If an accredited laboratory fails any two rounds of proficiency testing within a set of three 

consecutive rounds, its accreditation will be immediately suspended. To regain accreditation, the 

laboratory may undergo a complete on-site assessment and proficiency test to determine the cause of the 

nonconformities, and within 30 days provide documentation to NVLAP to demonstrate that effective 

corrective actions have been implemented. Failure to perform satisfactorily at the on-site assessment will 

result in continued suspension of the accreditation. 

The full cost of any reassessment shall be paid in advance. NVLAP staff will make every effort to 

expedite these extraordinary assessments to give a laboratory every reasonable opportunity to demonstrate 

competence to perform the test method and regain accreditation. 

3.4.13 Failure to participate in a round of proficiency testing will result in the immediate suspension of 

accreditation. To have the accreditation reinstated, the laboratory shall pass the next regularly scheduled 

round of proficiency testing. 

8 NIST Handbook 150-3:2006 
4 Management requirements for accreditation 

4.1 Organization 

4.1.1 The laboratory shall be organized so that staff members are not subjected to undue pressure or 

inducement that might influence their judgment or the results of their work. 

4.1.2 A laboratory operating as a sub-facility shall be technically dependent on the main facility. The 

main facility shall provide technical management and supervision in accordance with the following 

requirements. 

a) The nature, scope, and frequency of on-site quality assurance reviews by the main facility quality 

manager shall be clearly defined in the management system and be appropriate for the nature and 

scope of work performed by the sub-facility. 

b) Copies of all permanent quality assurance and personnel records shall be retained at the main 

facility. 

c) Quality assurance data from each sub-facility shall be frequently and routinely compared both to 

the main facility’s data and data from other sub-facilities. 

d) Records of such comparisons shall be retained in quality assurance records along with actions 

taken to evaluate and resolve nonconformities. 

4.1.3 NVLAP accreditation of a laboratory main facility does not extend to accreditation of subfacilities unless the sub-facilities have been evaluated separately. These facilities are uniquely identified 

in the NVLAP accreditation documents. 

4.2 Management system 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.3 Document control 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.4 Review of requests, tenders and contracts 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.5 Subcontracting of tests and calibrations 

4.5.1 A laboratory that subcontracts its AHERA work shall ensure that the subcontracted laboratory is 

accredited by NVLAP for bulk asbestos analysis. [See also NIST Handbook 150, 5.10.2 b), 5.10.6, and 

Annex A, A.1 i).] 

NIST Handbook 150-3:2006 9 
4.5.2 A NVLAP-accredited laboratory shall not represent test data produced at a non-accredited subfacility as having been produced by an accredited laboratory. 

4.6 Purchasing services and supplies 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.7 Service to the customer 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.8 Complaints 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.9 Control of nonconforming testing and/or calibration work 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.10 Improvement 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.11 Corrective action 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.12 Preventive action 

There are no requirements additional to those set forth in NIST Handbook 150. 

4.13 Control of records 

The period of retention of records shall be three years, unless a longer period is required by the client, 

regulation, or the laboratory’s own procedures. The records to be maintained shall include: 

a) sample custody records; 

b) original data collected, signed (or initialed), and dated by analyst; 

c) contamination monitoring data; 

d) calibration and verification data; 

10 NIST Handbook 150-3:2006 
e) data and results of quality control; 

f) equipment and maintenance records; 

g) test reports; 

h) records of proficiency testing results for each analyst. 

4.14 Internal audits 

4.14.1 The internal audit shall cover compliance with NVLAP, laboratory management system, 

regulatory, contractual, and testing requirements. 

4.14.2 An applicant laboratory shall conduct at least one complete internal audit prior to the first on-site 

assessment. The records will be reviewed by the NVLAP assessor before or during the on-site 

assessment visit. 

4.14.3 For accredited laboratories, internal audit reports conducted since the previous on-site assessment 

shall be made available for review. 

4.14.4 Internal audits are separate and distinct from management reviews (see 4.15). 

4.15 Management reviews 

4.15.1 Periodic reviews of the management system shall reflect adherence to NVLAP requirements and 

the laboratory’s quality objectives. 

4.15.2 Management reviews shall review all nonconformities and may reflect positive aspects of the 

management system. 

4.15.3 An applicant laboratory shall perform at least one complete management review prior to the first 

on-site assessment. The records will be reviewed by the NVLAP assessor before or during the on-site 

assessment visit. 

4.15.4 The report of the management review shall be available during the NVLAP on-site assessment. 

5 Technical requirements for accreditation 

5.1 General 

There are no requirements additional to those set forth in NIST Handbook 150. 

5.2 Personnel 

5.2.1 The laboratory shall have a detailed, documented description of its training program for new and 

current staff members. The analytical results obtained by new staff members shall be checked by an 

NIST Handbook 150-3:2006 11 
analyst whose performance has been demonstrated to be acceptable, or by using an independent 

technique, until the new staff member demonstrates the required level of performance. The laboratory 

shall establish and document performance criteria to determine when a new analyst is qualified to work 

independently. Reference documents, texts, journals, and current scientific and industry periodicals shall 

be made available to all analysts to keep their knowledge up to date and shall include, as a minimum, the 

documents listed in Annex A. An ongoing process of practice, training and professional development is 

essential to the maintenance and improvement of analyst expertise. 

5.2.2 A laboratory analyst shall be able to obtain enough information from the laboratory’s quality 

documentation to perform analyses in the absence of the laboratory manager. Specific evidence that all 

staff members have been trained for their role in the quality assurance program is required. 

5.2.3 All analysts and technical supervisors shall understand polarized light microscopy and its 

application to crystalline materials. They shall understand what measurements are possible with the 

PLM, how they are performed, and how to form conclusions about the identity of a component from the 

measurements. They shall be able to measure all optical properties required for the identification of 

regulated asbestos types, and in particular, the index of refraction by the immersion method. These 

measurements shall be satisfactorily performed, upon request, during an on-site visit by a NVLAP 

assessor. Knowledge of several techniques of refractive index measurement (e.g., Becke line, dispersion 

staining, and oblique illumination), in addition to other analytical methods (e.g., x-ray diffraction, 

transmission electron microscopy, and scanning electron microscopy) are also helpful. 

5.3 Accommodation and environmental conditions 

5.3.1 The laboratory shall have the proper facilities to perform asbestos analysis, to store asbestos in 

accordance with federal, state and local laws, and to maintain sample integrity. 

5.3.2 The workspace shall be monitored for asbestos contamination on a routine basis. Laboratory 

blanks, using asbestos-free materials, shall be prepared and analyzed with sufficient frequency to detect 

contamination of laboratory equipment or supplies, including, but not restricted to, glass slides, cover 

slips, refractive index liquids, sampling instruments, analytical instruments (microscopes), workstations, 

and cleaning fluids. There shall be written procedures for dealing with any contamination. 

5.3.3 Safe working conditions shall be maintained while handling bulk asbestos. 

5.4 Test and calibration methods and method validation 

5.4.1 General 

The laboratory’s accreditation is limited to the test method contained in the U.S. EPA Interim Method, 

EPA/600/M4-82-020, 1982 (see 1.4), or the current EPA method for the analysis of asbestos in building 

material. The laboratory shall have written procedures that describe how the method is implemented in 

the laboratory and shall conform in all respects with the test method except when a departure becomes 

necessary for technical reasons. When a departure is necessary, it shall be stated on the laboratory’s test 

report. 

12 NIST Handbook 150-3:2006 
5.4.2 Selection of methods 

EPA/600/R-93/116, 1993 (see 1.4), provides clarifications and improvements to the 1982 EPA Interim 

Method. Specifically, use of the improved method can provide more precise analytical results, especially 

at low asbestos concentrations, enhanced analysis of floor tiles that may contain thin asbestos fibers 

below the limits of resolution of the PLM, and clearer instruction on the analysis of bulk materials, 

particularly where multiple layers are present. 

5.4.3 Validation of methods 

The laboratory shall have data to demonstrate that departures from the test method do not detract from the 

expected precision and/or accuracy of the measurement. Laboratories utilizing departures from a test 

method shall have written procedures detailing how the analysis is conducted. These procedures shall 

include criteria to determine when such departures are warranted. 

5.4.4 Estimation of uncertainty of measurement

5.4.4.1 The detection limit for asbestos is a function of the analyst’s capabilities, the laboratory’s reliable 

blank level, and the visibility of asbestos in the sample (a function of microscopic image, contrast and 

resolution, asbestos fiber size, sample matrix, slide preparation, etc.). The level of quantification may be 

defined as the concentration at which a statistical uncertainty is determined for the quantity of asbestos 

reported. The uncertainty may be determined by analysis of standard materials and is a function of the 

same parameters listed for the limit of detection. If a method other than the point count is used for 

quantification, the level of quantification for the method shall be determined and documented by the 

laboratory in order to report the presence of a trace of asbestos. 

5.4.4.2 The PLM technique is dependent on the amount of asbestos in the sample and the characteristics 

of the matrix. Laboratories should recognize this and incorporate provisions for addressing it into their 

management system. An example of the variability that can be expected with concentration is given in 

EPA/600/R-93/116, 1993. NVLAP proficiency testing materials, or typical manufactured standards, give 

the concentration of asbestos in units of weight percent; however, the PLM technique yields results in 

units of relative area. The conversion of weight percent to area percent requires knowledge of the density 

and relative grain size of the components of the sample—factors that are often not easily determined. 

However, the difference between weight percent and area percent is often obscured by the semiquantitative nature of the PLM technique; for many samples there is no significant difference between 

weight and area percent results. The exceptions to this statement occur when the sample contains 

components (such as organic materials) that have a very different density than the asbestos minerals or 

when there is a large disparity in relative grain size. It is recommended that laboratories use weight 

percent and point-counted standards when training an analyst for quantification of asbestos by the PLM 

technique. 

5.4.4.3 There shall be an error rate of less than 1 % on qualitative analysis. The laboratory shall monitor 

the error rate and use it as a guide to determine when an analyst requires additional training to ensure the 

integrity of measurements. Samples that present particular difficulty shall be identified and specific 

procedures shall be described for analyzing them, which may include sample rejection or the use of 

additional analytical or sample preparation techniques. 

NIST Handbook 150-3:2006 13 
5.4.5 Control of data

Computerized systems that provide default optical measurements do not meet NVLAP requirements. 

Laboratories shall have documentation to show that analysts are measuring optical data by PLM 

examination. 

5.5 Equipment 

5.5.1 The laboratory shall have the following equipment and supplies for the performance of the tests 

and measurements required for bulk asbestos analysis: 

a) polarized light microscope with the following characteristics: binocular or monocular; one of the 

oculars shall have a cross hair reticle or functional equivalent that does not rotate during normal 

operation of the microscope; one of the oculars shall have a magnification of at least 8 X; and 

objectives low (≥ 5 X and ≤ 15 X), medium (> 15 X and < 40 X), and high (≥ 40 X), or similar 

magnifications; light source; 360o rotatable stage; substage condenser with iris diaphragm; 

polarizer and analyzer that can be placed at 90o to one another; accessory slot for wave plates and 

compensators; wave retardation plate (approximately 550 nm retardation); 

b) low-power binocular microscope or stereomicroscope that will not move during normal 

operation, approximately 10 X to 45 X, with light source; 

c) sampling utensils (tweezers, razors, knives, forceps, probe needles, pliers, etc.); 

d) sample containers (glassine paper, glass plates, ceramic bowls, petri dishes, etc.); 

e) microscope slides and cover slips; 

f) refractive index liquids: 1.490 - 1.720, in increments of ≤ 0.005 and calibrated with an accuracy 

of ± 0.004; 

g) mortar and pestle; 

h) thermometer that will allow the laboratory to meet NVLAP requirements (a laboratory 

thermometer from a reputable scientific supply company is acceptable); 

i) calibrated refractive index solids or refractometer (or access to) for the calibration of refractive 

index liquids. 

5.5.2 In addition to the equipment and supplies listed in 5.5.1, a biohazard hood of Class I or better, or 

a re-circulating hood with a HEPA filter (glove box) is required for the safe and non-contaminating 

handling of bulk asbestos materials in the laboratory. For this program, the purpose of the hood is to 

protect the laboratory environment from contamination with the potentially large quantities of asbestos 

handled during routine preparation and macroscopic examination of building materials. A Class I hood is 

a ventilated cabinet for personnel and environmental protection, with an inward airflow away from the 

operator. The cabinet exhaust air shall be treated to protect the environment before it is discharged to the 

outside atmosphere or shall exhaust HEPA-filtered air back into the laboratory. A minimum inward 

velocity of air into the hood opening of 38 X 10-2 m/s (75 fpm) is recommended. 

14 NIST Handbook 150-3:2006 
5.5.3 The following equipment and supplies are optional for the laboratory: 

a) dispersion staining objective or functional equivalent; 

b) high dispersion refractive index liquids; 

c) blue "daylight" filter for white light balance; 

d) monochromatic (≈589 nm) filter or functional equivalent; 

e) mechanical stage and/or point-counting stage; 

f) mill and/or blender; 

g) analytical balance (readability of 1 mg or better); 

h) muffle furnace (temperature range to 500 °C or higher, stable to ± 10 °C or better)*; 

i) drying oven*; 

j) hydrochloric acid (recommend 10 % by volume)*; 

k) filtration supplies. 

NOTE It is recommended that the items marked by an asterisk (*) be performed in an exhaust hood. 

5.5.4 The periodic cleaning and maintenance of all microscopes by qualified professional technicians is 

recommended. Routine maintenance of the PLM shall be performed, including: 

a) alignment of the light source and substage assembly to provide proper illumination; 

b) centering of objectives; 

c) focusing of the cross hair reticle in the field of view; 

d) testing for coincidence, between the cross hair reticle and the privileged direction of the polarizer 

and analyzer; 

e) determining whether the polarizer and analyzer are normal to one another. 

5.6 Measurement traceability 

5.6.1 The use of standards, such as NIST Standard Reference Materials, other reference materials, and 

samples that have been well-characterized by intra- and inter-laboratory testing, such as samples from 

past NVLAP proficiency test rounds, AIHA, or other proficiency testing programs, and alternate methods 

of analysis are the best ways to ensure measurement accuracy. Specific preparation techniques may be 

used for samples to be used as standards, such as those found in Appendix C of EPA/600/R-93/116, 1993. 

NOTE It is highly recommended that NIST Standard Reference Materials for asbestos, when available, are 

purchased to achieve traceability. 

NIST Handbook 150-3:2006 15 
5.6.2 Assistance for the calculation of accuracy, precision and required quantification leading to the 

generation of control charts can be found in many analytical chemistry texts. Laboratories may refer to 

the following documents that are available for statistical techniques for bulk asbestos analysis using PLM: 

EPA/600/R-93/116, 1993, NISTIR 5951, and Guide to Statistical Analysis of Bulk Asbestos Quality 

Control Data (see 1.4). 

5.6.3 Precision and accuracy of analyses shall be determined on the types of samples received for 

analysis. 

Precision is the ability to repeat a measurement, and can be determined by comparing the results of a 

single sample by multiple analysts and/or from multiple analyses by the same analyst. 

Accuracy describes the correctness of a measurement and can be determined using materials of known 

concentration, such as past NVLAP proficiency testing materials, prepared standards (in-house or 

purchased), or materials analyzed by an independent technique. Appendix C of EPA/600/R-93/116, 

1993, describes how bulk asbestos samples can be prepared for use as training standards. 

5.6.4 For qualitative analyses, the laboratory shall determine whether multiple analyses of the same 

sample, either by the same or different analysts, and/or by different analytical techniques, yield the same 

results (asbestos present or not, and type of asbestos) and whether they are correct. 

5.6.5 For quantitative analyses, the laboratory shall determine an average value for the concentration of 

asbestos in the sample with an associated measurement uncertainty. The uncertainty can be determined 

from several analyses conducted on known quality assurance standards. The precision in the quantitative 

analysis of a sample by a single analyst is typically defined by the variation observed among multiple 

slides prepared from the sample or through blind reanalysis of a particular sample. Quantitative results 

should be represented in the form of tabulated numeric values for each analyst on the various materials. 

5.6.6 Control charts documenting precision, accuracy and error rates shall be prepared to assist 

laboratory personnel in characterizing the overall laboratory and individual performance. Analyst 

precision and accuracy data shall be documented and reflected in the required monthly summaries. These 

summaries should be filed appropriately and will undergo evaluation during NVLAP on-site visits. All 

procedures for such measurements shall be documented in the management system documentation. 

5.7 Sampling 

Specific sampling procedures shall be documented where appropriate. This is especially important for 

samples containing multiple layers. 

5.8 Handling of test and calibration items 

5.8.1 It is recommended that sample receipt and handling during log-in be conducted in a HEPAfiltered, Class I biohazard hood, or a glove box with continuous airflow (negative pressure) (see 5.5.2). 

5.8.2 Samples shall be held for at least 30 days unless client specifications or regulations state 

otherwise. It is recommended that clients be notified of the sample disposal policies of the laboratory. 

16 NIST Handbook 150-3:2006 
5.8.3 Because of the legal issues surrounding asbestos analysis, laboratories may consider keeping 

samples indefinitely or returning the samples to the client with a signed chain-of-custody form. 

5.8.4 Samples shall be stored so that sample identification is properly maintained and samples can be 

readily retrieved. 

5.9 Assuring the quality of test and calibration results 

5.9.1 Analyst proficiency is the key to providing reliable data. All analysts shall be tested routinely to 

evaluate their performance. Test results shall be recorded in the personnel folder, or equivalent, of each 

staff member, and be available during NVLAP assessments. Testing techniques may include, but not be 

limited to, reanalysis of materials, intra- and inter-laboratory comparisons, analysis of standards, 

reference materials, NVLAP proficiency testing materials, and blind testing. 

5.9.2 Testing shall be frequent enough to ensure quality analyses. Test specimens shall include 

asbestos-containing and look-alike materials routinely examined by the analysts, and those not often 

encountered. Problems shall be discussed with the analyst, and corrected according to documented 

procedures. Subsequent quality assurance tests shall determine whether the problem has been corrected

and the laboratory shall ensure the quality of analyses while the problem is being corrected. All 

corrective actions shall be documented in monthly quality assurance summaries, periodic laboratory 

audits, and individual analysts’ files. Historical data has shown that visual estimation tends to have a high 

bias. Laboratories shall monitor precision data to determine if there is a problem in this area. 

5.9.3 Additional information and techniques are found in EPA/600/R-93/116, 1993. 

5.10 Reporting the results 

5.10.1 To document the positive identification of asbestos in a sample, the analyst shall record the 

average optical properties for the population of each asbestos type, including morphology, color and 

pleochroism, indices of refraction (nD), birefringence, extinction characteristics, sign of elongation, and 

any other distinguishing characteristics observed. For chrysotile and amosite, refractive indices shall be 

determined parallel and perpendicular to elongation with an accuracy of ± 0.005. For anthophyllite, 

tremolite, and actinolite, α and γ, instead of refractive indices parallel and perpendicular to elongation, 

and shall be measured if the population of fibers display biaxial optics; otherwise the requirements for 

chrysotile and amosite apply and shall be determined with an accuracy of ± 0.005. For crocidolite, the 

refractive indices shall be determined parallel and perpendicular to elongation with an accuracy of 

approximately ± 0.01. 

5.10.2 If original data are entered using a computer, analysts shall type the determined refractive indices 

into the corresponding fields. A set of fixed default values of refractive indices for respective asbestos 

types automatically generated by the computer is not acceptable (see 5.4.5). 

5.10.3 When reporting the percentage of asbestos in a sample, the following shall be considered: 

a) The asbestos phase(s) shall be positively identified by PLM and the optical parameters recorded 

before stating that asbestos is present in any quantity, including trace. 

b) The reported quantity of asbestos, including trace, should be consistent on the slide mounts used 

for quantification. This assumes that the sample is reasonably homogeneous or has been 

NIST Handbook 150-3:2006 17 
homogenized to ensure that each sub-sample is representative of the composition of the total 

sample. 

c) A point count or equivalent method is required for quantification. If asbestos is counted during 

the point count, the percentage should be reported; if asbestos is consistently observed but not 

counted, trace should be reported; if no consistent quantity of asbestos is observed, zero 

concentration should be reported. 

5.10.4 In addition to the test report requirements found in NIST Handbook 150, the following 

information shall be reported for each sample: 

a) the presence or absence of asbestos and the identification of each asbestos type; 

b) the estimate of the average area percentage (or weight percentage) for each type of asbestos 

present; 

c) the identity and area percentage of other fibrous and matrix materials, if known; 

d) both color and macroscopic description (and any other information that serves to identify and 

describe the sample). 

5.10.5 A laboratory using analytical techniques in addition to PLM that yield results in terms of weight 

percent (e.g., gravimetry or x-ray diffraction) may report results in weight percent. 

6 Additional requirements 

There are no additional requirements beyond NIST Handbook 150 and its associated normative annexes, 

and any other normative references previously cited in this handbook. 

18 NIST Handbook 150-3:2006 
Annex A 

(normative) 

Documents required in the laboratory 

The following documents shall be available at the laboratory: 

a) NIST Handbook 150, NVLAP Procedures and General Requirements; 

b) NIST Handbook 150-3, NVLAP Bulk Asbestos Analysis; 

c) Asbestos-containing Materials in Schools, Final Rule and Notice, as found in the Federal 

Register, Volume 52, No. 210, pages 41826 - 41846; 

d) U.S. Environmental Protection Agency Method for the Determination of Asbestos in Bulk 

Building Materials (EPA/600/R-93/116), 1993, R. L. Perkins and B. W. Harvey; 

e) NIST Technical Note 1297, 1994 Edition, Guidelines for Evaluating and Expressing the 

Uncertainty of NIST Measurement Results, Barry N. Taylor and Christ E. Kuyatt (available from 

NVLAP); 

f) reference text(s) on optical mineralogy and crystallography; 

g) general references text(s) on statistics and quality assurance. 

NIST Handbook 150-3:2006 19