NBSIR 88-3821THE
ABC's OF CERTIFICATION ACTIVITIES
IN THE UNITED STATESJuly
1988Maureen A. Breitenberg
Office of Standards Code
and Information
Office of the Associate Director for Industry and Standards
National Bureau of Standards
Gaithersburg, MD 20899
Foreword
Acknowledgments
Abstract
Introduction
Historical Notes
Product Quality
Self-Certification
Third-Party
Certification
Third-Party Certification Programs
in the United States
Federal Government Certification
Programs in the United States
State Certification Programs
in the United States
International and Regional
Certification Programs
Choice of Standards
Certification
Methodology
Certificates or Marks of Conformity (Certification Marks)
Potential Problems with Certification Programs
Summary
Footnotes
The Office of Standards Code
and Information periodically develops and publishes standards-related documents
as a service to producers and users of standards and certification programs, both
in government and in the private sector. This report is a sequel to NBSIR 87-3576,
The ABC's of Standards-Related Activities in the United States, and is designed
to provide the reader with additional information on one standards-related activity
-- certification. This document is a further introduction to certification for
those not fully familiar with this complex field. We hope that this material will
be informative and will serve to stimulate wider understanding of the purpose
and nature of certification. In addition, the interested reader may wish to take
advantage of other available publications and services provided by this office,
some of which are described in the appendix. Questions concerning this
document and any comments or suggestions to improve its format or content will
be welcome. Donald R. Mackay
Manager, Office of Standards Code and
Information
National Bureau of Standards
Administration Bldg., Rm. A-629
Gaithersburg, MD 20899 Return to Contents
I would like
to thank Foster Wilson, Charlie Hyer (the Marley Corp.), Jack Wyatt (DOD), Hank
Collins (UL), and many others for their careful review of and comments on this
document. Maureen A. Breitenberg
Office of Standards Code and Information Return
to Contents
This
report, a sequel to NBSIR 87-3576, The ABC's of Standards- Related Activities
in the United States, provides a further introduction to certification for a reader
who is not entirely familiar with this topic. It highlights some of the more important
aspects of this field, furnishes the reader with information necessary to make
informed purchases, and serves as background for using available documents and
services. Key Words: certificates of conformity; certification; certification
marks; conformance testing; inspection; product listing; quality assurance; standardization;
standards; testing Return to Contents
We live in a
perpetually changing world in which technological innovations keep pushing the
boundaries of our knowledge. Yet in order to survive, there is a need to regulate
-- to standardize aspects of our surroundings. Nowhere is this more true than
in the marketplace. A state-of-the-art computer is of no benefit without compatible
software. Nor does one want to purchase a technologically superior new appliance
only to find that its plug does not fit the outlet; or, worse yet, appears to
fit, but in fact increases the potential for fire or electrical shock. Some
characteristics of products need to be standardized, and certification programs
are a vital link between standards for such products and the products themselves.
Certification programs provide a means of assuring that a product has the characteristics
or meets the requirements contained in a standard. One definition of a
certification program or scheme is "the procedure by which written assurance
is given that a product or service conforms to a standard or specification,"
1/ but almost as many definitions for a certification program exist as there are
organizations attempting to define it. In addition, some organizations use other
terms to refer to the process, such as product listing, product evaluation,
product regulation, product approval, or the publication of research reports.
Product certification schemes range from the simple to the complex. There
are many private organizations, as well as federal and state agencies in the United
States, which certify products ranging from electrical cords to meat products.
In addition, many certification programs are operated at local government levels.
Consumers see evidence of the extensiveness of certification- related activities
when they note the Underwriters Laboratories (UL) mark on such products as electric
coffee pots and fire extinguishers, the U.S. Department of Agriculture (USDA)
mark on poultry and other agricultural products, and the International Wool Secretariat's
Woolmark or Woolmarkblend on wool and wool blend textile goods. These are only
a few of the many certification marks which appear on products consumers purchase. The
impact of certification programs on trade in both domestic and international markets
has become increasingly prominent. The international General Agreement on Tariffs
and Trade (GATT) has as one of its major components the Agreement on Technical
Barriers to Trade (usually referred to as the Standards Code). The framers of
the Standards Code, including the United States, recognized that activities such
as certification programs can expedite or seriously hinder the free flow of goods
in international commerce. The Code established, for the first time, procedural
requirements for certification schemes to avoid the establishment of unnecessary
obstacles to trade. The Code also ensures that non-discriminatory access to certification
programs will be provided to foreign suppliers. A fundamental principle of the
Code is the proviso that national or regional certification schemes are to grant
access to foreign suppliers in signatory countries under conditions no less favorable
than those granted to domestic suppliers. 2/ The Trade Agreements Act of 1979,
which implemented the Standards Code in the United States, enacted similar guidelines
within the United States to discourage certification schemes that might create
unnecessary obstacles to trade. Ideally, however, a properly conducted certification
program benefits, not hinders, the free flow of goods into the marketplace. Certification
verifies that a particular product meets a given level of quality or safety, providing
the user with explicit or implicit information about the characteristics and/or
performance of the product. Certification can also increase a buyer's confidence
in a product and furnish useful product information.(1) Because certification
schemes have a significant impact on the marketplace, it is important to have
some familiarity with certification terminology and to understand why different
types of certification programs provide users with varying amounts of information
and degrees of confidence in the resultant certification. This paper is intended
to be an introduction to some of the more vital aspects of product certification.
It will also discuss some of the benefits and problems associated with certification.
Interested readers are encouraged to increase their knowledge of the field by
taking advantage of other available publications and services described in the
paper, footnotes and appendix. Return to Contents
An inscribed
stone of the 4th Century BC, found in Eleusis, Greece in 1893, cited a decree
regarding the manufacture of bronze fittings for the erection of the columns of
a new stoa (portico) which became the Philonion Stoa. The bronze specified was
copper/tin in a ratio of 11 parts copper to 1 part tin. Professor Varoufakis in
his book, Materials Testing in Classical Greece, Technical Specifications of the
4th Century BC, 3/ argued that the discovery of such a specification implies the
existence of some type of check or verification. Professor Varoufakis tested the
possibility that this check could have been conducted based on color differences
between polished specimens of bronze differing in tin content. He noted a distinct
color difference between two specimens when the tin content differed by only 2%.
A similar process for identifying and differentiating gold alloys was already
in use in ancient Greece. These may have been two of the earliest forms of certification
-- metals of unknown content certified as to their composition on the basis of
inspections for color. One of the most ingenious and lasting forms of certification
was coinage. When lumps of gold or other precious metal became units of value
and weight (the two being indistinguishable) they were marked with an official
seal, ultimately becoming certified ingots or what are today known as coins. This
did not, however, stop early attempts to circumvent such certifications -- chiseling
bits of metal from the ingots or coins. In fact, the English language retains
the term "chiseler" as a memorial to the men who figured out difficult-to-detect
methods for chiseling metal from certified ingots and coins. 4/ From 1890
to 1900, when the use of gas for domestic cooking and heating began to gain widespread
popularity, many new gas appliances were developed and sold. Early records indicate
that some thought was given to establishing a gas appliance testing laboratory
as early as 1903. The Baltimore investigation, conducted by the National Bureau
of Standards in 1923, analyzed accidents resulting from the use of domestic gas
appliances and flexible gas tubing. The City of Los Angeles started a similar
laboratory and field study in 1924. Both investigations pointed to the need for
a certification program for gas appliances. In 1925, the American Gas Association
established a laboratory to test and certify gas appliances. The first certified
gas heaters and ranges appeared on the market in 1926. Just 50 years ago,
U.S. drug manufacturers could produce and sell drugs without testing them on either
animals or humans and without any kind of governmental approval. Governmental
action could only be taken against drugs which were misbranded or adulterated.
In 1937, physicians in Tulsa, Oklahoma reported to the American Medical Association
(AMA) the deaths of six patients from a liquefied version of the then wonder drug
sulfa. Ultimately this drug killed 107 people, mostly children, before doctors
realized what was happening and the drug was recalled. This tragedy led to the
enactment of the 1938 Food, Drug and Cosmetic Act, which requires that drugs be
tested and approved by the Food and Drug Administration before marketing. Roofing
systems are composed of a deck, its cover, insulation, vapor barriers, adhesives,
and fasteners. These systems are required to withstand many stresses and hazards.
Three materials are used in roof decks -- concrete, steel and wood. It was initially
believed that fire spread under a deck was a problem for wood construction only.
This was one reason the steel deck was rapidly adopted after its introduction
during the post World War II years. The 1953 Livonia Michigan fire proved this
assumption wrong when fire spread rapidly under a steel deck. Subsequent testing
showed that, although the deck itself was not combustible, the adhesive, vapor
barrier and insulation used frequently were. Once these materials are heated,
they produce gases which, if they can't escape through the roof's covering, are
forced through the joints of the deck, where they can ignite and spread along
the underside. 5/ This discovery demonstrated the need for the certification of
not only individual roofing products, but of total roof construction, for fire
spread and heat release. From such early beginnings, the certification industry
has grown both in size and complexity. Return to Contents
The quality of
any product depends on two major elements: - The design and formulation
of the product; and - The care and consistency of the manufacturing process. The
design and formulation of the product can generally be evaluated against specific
criteria by physically testing a prototype (or preproduction model) or by reviewing
the product's design specifications. Prototype models, which are not necessarily
identical to the actual production line output, indicate how a product coming
off the assembly line might perform. While successful prototype testing does not
necessarily ensure that the production model will perform as expected, such tests
are helpful in achieving some assurance of adequate product safety or quality. The
manufacturing process depends on many variables, such as quality of the components
or materials, equipment, equipment calibration and maintenance, the training and
experience of production and supervisory personnel, the level of "workmanship,"
and sometimes the environmental conditions (temperature, humidity, level of dust
particles) in the area where the product is produced. The process manufacturers
use to control these variables to produce a product of consistent quality or which
meets defined specifications is called a quality control or quality assurance
(QA) system. Fundamental to W. Edwards Deming's approach to management is
that "quality comes not from inspection, but from improvement of the production
process." 6/ Improvements made to the design of the product and the quality
of the manufacturing process have the greatest impact on product quality. "Inspection
to improve quality is too late, ineffective, costly." 7/ The International
Organization for Standardization (ISO) has published a series of five International
Standards (ISO 9000, 9001, 9002, 9003, and 9004) on the subject of quality assurance
which, together with the terminology and definitions contained in ISO Standard
8402, provide a practical and generally applicable set of principles for QA systems.
ISO 9000 provides guidance on the selection of the specific quality management
program most likely to be appropriate for a manufacturer's operations. ISO 9001,
9002 and 9003 describe three distinct quality assurance models of varying stringency,
and ISO 9004 examines each of the quality system elements (cross-referenced in
ISO 9000) in greater detail. The ISO 9000 Series provides excellent guidance
and information on basic requirements for quality management in manufacturing
industries. The ISO Series can also be used for general guidance in service industries. There
is also a growing trend regarding the implementation of quality assurance registration
(sometimes misnamed "quality assurance certification"), which may or
may not be independent of any certification program. These registrations involve
the assessment and periodic audit of the effectiveness of a manufacturer's QA
system. A manufacturer can register his QA system with an organization which conducts
a quality assurance registration program without participating in a product certification
program. The ISO 9000 series has been used as the basis for the development of
many such programs internationally. Return to Contents
Self-certification
is the process by which a manufacturer or supplier declares that his product meets
one or more standards based on: (1) his confidence in his quality control system,
or (2) the results of testing or inspection he undertakes or authorizes others
to undertake on his behalf. In other parts of the world, this process is also
known as a manufacturer's declaration of conformance. The manufacturer's
capability, integrity, and reputation determine the degree of confidence that
can be placed in self-certification. In the United States, the criteria
and procedures recommended for a self-certification program are established in
American National Standards Institute (ANSI) Standard Z-34.2-1987, "American
National Standard for Certification - Self-Certification by Producer or Supplier."
Such procedures include the requirement that self- certification be based on conformance
with all requirements of a standard unless full disclosure is made of any limitations
of the certification. There are also requirements for the adequate use and maintenance
of test equipment, an effective quality control system, fully-trained staff, written
certification procedures, and adequate record keeping. One of the most familiar
certification programs in the United States involves the identification of the
weight of motor oils by the manufacturer of conformance to the Society of Automotive
Engineers (SAE) standards. Consumers will recognize such weight designations as
SAE 10W-40W or 10W-30W on the motor oils they buy. These SAE designations are
placed on the motor oils by the manufacturer based on testing and quality control
mechanisms. This is primarily a self-certification program, though SAE
does audit manufacturers' self-certifications to ensure that SAE standards are
not being misused. Return to Contents
Third-party
certification, on the other hand, is "a form of certification in which the
producer's claim of conformity is validated, as part of a third-party certification
program, by a technically and otherwise competent body other than one controlled
by the producer or buyer." 8/ The sponsor of the third-party program (the
certifier) may be responsible for collecting the required data, generating test
results or conducting inspections, in addition to reviewing the results of such
activities and making a final determination on the product's conformance or lack
of conformance. Or the certifier may delegate all or part of the data collection
and review activities to another party or parties. The degree of confidence that
can be placed in third-party certification programs varies greatly depending on
(1) the number and types of testing/inspection methods used within the program
to assure product conformance, (2) the adequacy of the manufacturer's quality
control system, and (3) the competence of the body which conducts the testing
and/or inspection and evaluates the test results. Recommended criteria and
procedures for third-party certification programs in the United States are established
in ANSI Standard Z- 34.1-1987, "American National Standards for Certification
- Third- Party Certification Program." Return to Contents
Private third-party certification programs in the
United States are operated by many different types of organizations including: -
Professional or technical societies, such as the American Dental Association(ADA); -
Trade associations, such as the Association of Home Appliance - Independent
testing/inspection organizations, such as Underwriters Laboratories (UL), Factory
Mutual Research Corp. (FM), ETL Testing Laboratories, and the MET Electrical Testing
Company; - Organizations oriented toward consumers, industrial buyers, or
users of the product or service, such as Good Housekeeping magazine, which offers
a consumer protection program for products it approves; - Organizations
composed of producers, testing laboratories, and others concerned with the well-being
of an industrial group and/or its customers, such as the Solar Rating and Certification
Corp. (SRCC), a nonprofit organization founded in 1980 to certify performance
and rate solar energy equipment; - Organizations comprised of government
officials involved in the regulation of an industry, such as the Building Officials
and Code Administrators International (BOCA), the International Conference of
Building Officials (ICBO), the Southern Building Code Congress International (SBCCI),
and the International Association of Plumbing and Mechanical Officials (IAPMO);
and - Other miscellaneous organizations, such as a ship classification society. One
of the oldest certification programs has been operated since 1870 by the American
Bureau of Shipping (ABS), a ship classification society. It is concerned with
the design, construction and periodic survey of merchant ships and other marine
structures. ABS certifications cover over 14,900 vessels and 1,000,000 cargo containers.
Other certified products include: mobile offshore drilling and production units,
fixed offshore structures, work boats, cranes, yachts, cargo handling engines,
and related machinery and materials. Another well established industry trade
association certification program is that of the American Gas Association (AGA),
operated since 1925. Over 260 manufacturers participate in AGA's program for gas
appliances and accessories. AGA currently certifies a wide range of products including
gas-fired central furnaces, gas cooking appliances and even gas-fired toilets.
Products are tested in AGA facilities and requirements for certification include:
a review of the construction and performance information for the product, factory
and quality control inspections and annual product testing/inspections. Additional
documentation may also be required. AGA publishes an annual directory of certified
appliances and accessories. More recently established appliance certification
programs for room air conditioners, refrigerator-freezers, dehumidifiers, and
humidifiers are operated by the Association of Home Appliance Manufacturers (AHAM).
The Air-Conditioning and Refrigeration Institute (ARI) certifies appliances ranging
from air conditioning equipment to water coolers and solar collectors. A
program familiar to many consumers is that of the American Dental Association
(ADA), a professional society which operates a program for certifying dental materials,
instruments, and equipment. The ADA certification program uses ADA standards and
requires the submittal of a detailed application describing the product's specifications.
ADA also requires self-certification by the manufacturer that the product meets
the standard. Product samples obtained on the open market are tested by ADA. Upon
approval, ADA authorizes the use of the ADA Seal of Certification. ADA also publishes
approved product lists. Most consumers take for granted the familiar "UL"
mark on a variety of products from electrical appliances to fire extinguishers.
The Underwriters Laboratories (UL), an independent testing laboratory founded
in 1894, is not only a major standards writer, but also tests products and materials
with respect to potential hazards to life or property, listing those items which
appear to pose no significant hazards. The Factory Mutual Research Corporation
(FM), is another "product listing" organization, similar to UL. It is
a non-profit testing and research organization whose purpose is to try to minimize
industrial property damage through a number of activities including product approval.
FM issues lists of approved products as different as industrial trucks and building
materials. Gardeners might recognize the AARS (All-America Rose Selections)
mark on the rose bushes they purchase. Over 40% of the roses sold in the United
States bear the AARS symbol. The AAS (All-America Selections) mark is used in
connection with seed for flowers and vegetables. The work of other major
certification organizations, although equally vital, may be less well known outside
the testing/inspection community. The National Certified Testing Laboratories
(NCTL), an independent testing laboratory, certifies many products from paint
to insulated glass. The Metallurgical Engineers of Atlanta (MEA) certifies carpet
under the Department of Housing and Urban Development (HUD) carpet certification
program developed by the Carpet and Rug Institute. The National Board of
Boiler and Pressure Vessel Inspectors (NBBI), an organization composed of chief
boiler inspectors in the United States and Canada, certifies boilers and components,
water heaters, pressure vessels, nuclear components and installations, and a number
of related products for conformance to the American Society of Mechanical Engineers
(ASME) codes. The value of certifying these products to ASME Codes is recognized
internationally. Several building code organizations, such as the Building
Officials and Code Administrators International (BOCA), the International Conference
of Building Officials (ICBO), and the Southern Building Code Congress International
(SBCCI), engage in certification- related activities. Composed of building, construction,
zoning, and inspection officials, these organizations have developed model building
codes which have been adopted by hundreds of state and local governments. The
organizations evaluate products and materials and approve them for conformance
with the requirements established in their building codes. In all, over
110 private sector organizations in the United States certify or list different
types of products. The broad range of organizations involved in certification
reflects the impact of certification on a vast spectrum of interests and disciplines.
(See NBS SP 703 for more information on these programs). Return
to Contents
Federal government
certification programs can be classified into several general categories: -
Programs to certify products which directly affect the health or safety of the
user or the general public. - Programs which test products in order to avoid
the necessity for retesting at local levels or prior to each procurement. -
Programs to provide a uniform basis for trade by assessing the quality and condition
of products offered for sale. 9/ Examples of the first type of certification
program include the evaluation and approval by the Food and Drug Administration
(FDA), U.S. Dept. of Health and Human Services, of new animal and human drugs,
medical devices, biologicals, and other products; the certification by the Federal
Aviation Administration (FAA), U.S. Dept. of Transportation, of airplanes and
major airplane components; and the certification by the Mine Safety and Health
Administration (MSHA), Dept. of Labor, of electrical equipment used in mines. An
example of the second type of program is the Dept. of Defense's (DoD) Qualified
Products Listing (QPL) Program for parts, materials and components used in military
systems. This program reduces retesting prior to each government purchase by testing
products and placing those approved on appropriate QPL's. An extension of this
concept also underlies the DoD Qualified Manufacturing Lists (QML's) Program,
in which a manufacturer's process controls and manufacturing capabilities are
evaluated and approved for an entire range of products. An example of the
third type of program is the U.S. Dept. of Agriculture (USDA) program to grade
and certify meat and meat products (on a voluntary basis) using uniform grading
standards for the buying and selling of such products. The USDA also certifies
dairy products, fresh and processed fruits, vegetables, nuts and related products.
The National Oceanic and Atmospheric Administration (NOAA), U.S. Dept. of Commerce,
likewise inspects and grades processed fish and shellfish at a seafood processor's
request. Return to Contents
States administer many
certification programs which cover a diversity of products for a variety of reasons.
In some cases, states inspect or test products under authority delegated by the
federal government. Many states inspect meat and meat products, certifying those
that meet standards established by the USDA. These states then authorize the use
of the appropriate USDA marks. Many states inspect and issue certificates of conformity
for manufactured homes under authority delegated by the U.S. Dept. of Housing
and Urban Development (HUD). States may also impose additional state requirements
and simultaneously check for conformity to these and federal requirements. States
also regulate products under their own authority for health and safety reasons,
including amusement rides and insulation, depending on each state's perception
of the health and safety impact of such products on its population. Products may
be inspected and/or tested directly by the states themselves, or indirectly through
a requirement that such products be inspected and/or tested and certified by an
approved body, such as a nationally recognized laboratory. An example of the latter
is the regulation of electrical products by imposing a state requirement that
they be tested/inspected and bear the mark of a "nationally recognized testing
laboratory." This term is currently interpreted individually by each state,
though the Occupational Safety and Health Administration is in the process of
developing criteria to define what constitutes a "nationally recognized laboratory." States
also regulate products of direct or indirect economic importance. Florida and
California, for example, inspect products important to their citrus fruit industry.
Nebraska, with a considerable agricultural industry, regulates tractors through
a testing program at the University of Nebraska and issues certificates of conformity
for approved models. California, with its air pollution problem, stringently regulates
auto emissions equipment. States also inspect/test/certify materials, products,
systems and services they procure, such as materials for the construction of state
roads and bridges. In yet other cases, the states establish standards and leave
enforcement (testing, inspection, etc.) to local authorities. This is sometimes
true for building and construction materials. Return to
Contents
The objectives of international
and regional certification schemes are: (1) to ensure an objective assessment
of product quality; (2) to increase the efficiency of international
or regional economic co-operation through the removal of technical barriers to
trade; (3) to quicken the circulation of products entering international
or regional markets; (4) to eliminate the need for retesting and
thus to reduce the testing/inspection costs incurred; and (5) to
ensure safety, health and environmental protection. In some cases,
a reciprocal certification scheme may be established whereby a certificate of
conformity (or license to label the product with a certification mark) is granted
in one participating country and recognized in other participating countries.
An example of this type of scheme at the regional level is the European Committee
for Electrotechnical Standardization (CENELEC) HAR Agreement - an agreement on
the use of a marking scheme for electrical cables and cords complying with harmonized
specifications. Cables and cords that bear the HAR mark or a colored thread marking
must be accepted without further testing or certification by the approval organizations
of participating countries. 10/ Another regional example is the CENELEC Electronic
Components Committee System (CECC) under which participants must accept certified
electronic components produced under this scheme without further testing. 11/ In
other types of schemes, provision may be made for the test report prepared in
one participating country to be accepted in other participating countries for
the purpose of obtaining certification or government marketing approval. Examples
are the programs coordinated by the European Free Trade Association (EFTA) for
pressure vessels, ships' equipment, agricultural equipment and tractors, liquid
fuel heating equipment, lifting apparatus (such as hoists, elevators, etc.) and
gas appliances. 12/ The required test report may have to establish conformity
with applicable standard(s) which have been harmonized (made technically identical
or equivalent in practice) between the importing and exporting countries or the
report may have to show compliance with technical requirements specified by the
importing country alone. In the latter case, the requirements of the importing
country may differ significantly from the requirements of the exporting country. Return
to Contents
The standards chosen for use in certification programs
should specify accurate and reproducible methods of testing for the specified
characteristics if the certification program is to have any validity. The standards
should also be clearly written and be capable of being uniformly interpreted.
However, there are many elements to consider when choosing standards for a certification
program. One of the most obvious considerations in selecting standards is
the determination of what product characteristics need to be assessed to achieve
the objectives of the program. The International Organization for Standardization
(ISO) has stated that standards suitable for product certification "....should
specify all those and only those characteristics and requirements that are necessary
to define the properties of the product or its performance;" and that, if
this is not possible, then reference should be made to other relevant standards.
13/ Unless the chosen standards do, in fact, adequately specify all product characteristics
that need to be assessed, it will not be possible to fully achieve the program's
objectives and the program's value may be questionable. Certification schemes
are normally established to indicate that a product meets one or more sets of
acceptable or minimum requirements. But what is acceptable? What may be acceptable
to one buyer may not be acceptable to another. Certification programs may choose
standards that result in certified products that satisfy a particular group or
organization, such as the government, or the program may choose standards expected
to satisfy a larger group of buyers or product users. The choice of standards,
therefore, may depend on the needs of the parties likely to use the certification. Standards
containing only one set of requirements and which define only one level of product
safety or quality are known as "pass- fail" standards. Either the product
meets the minimum requirements (it passes and is certified) or it does not (it
fails). Little or no attempt is made to convey information about the relative
safety or quality of one certified product compared to other certified products.
Unless other methods can be found to convey such information, a manufacturer may
be less motivated to produce products which exceed the minimum requirements specified
in the standard. Certifiers may therefore wish to provide information on
the quality or safety of one certified product relative to other certified products.
This may be accomplished by selecting standards which define several levels of
product safety or quality and by including a grading scheme in the certification
program. Information can be conveyed by stating the expected life of the product,
such as the expected number of miles that tires are supposed to travel, or the
versatility of the product, such as portable fire extinguishers rated for several
specified types of fires, or the efficiency of the product, such as the energy
efficiency rating for appliances. Buyers, assured of at least a minimum level
of safety and/or quality, can then choose among certified products based on any
additional level of quality or safety that they desire, other product characteristics
or features, and/or product price. A choice must also be made as to whether
the establishment of conformity should be based on an assessment of a product's
performance or its design. A performance standard, for example, may require that
a pipe be able to withstand a given level of pressure with no limitations on materials
used or on how the product is to be designed. A design standard, on the other
hand, might specify the material to be used, its thickness, and other design characteristics
to ensure that the resulting pipe could withstand a given level of pressure. All
standards are to some extent restrictive, but design standards limit flexibility
in product engineering and innovation to a greater extent than do performance
standards. For example, if the material specified for the pipe was plastic, then
a metal pipe would fail the certification process even if it could withstand greater
pressure than the plastic pipe. Performance standards, however, tend to be difficult
to develop and difficult to use in assessing product compliance. Problems may
arise in establishing reliable test methods for assessing conformity, thus potentially
increasing certification costs. The choice of standards for a certification
program has a significant impact on the validity of the program, the value of
the product information conveyed by the certification, and the program's cost. Return
to Contents
Third-party certification programs differ greatly from
one another, and the degree of confidence in the resultant certification depends
on the type of program and its comprehensiveness (the number and types of test/inspection
methods used within the program to assess conformity). The methods used
in third-party certification programs can be classified as follows: o Type-testing/Initial
Inspection - This method attempts to determine if the manufacturer's design
specifications can produce a product that conforms to a particular standard. Products
from a preproduction run are inspected and/or tested, but this method provides
no information on whether products from an actual production run also consistently
meet the specification. o Surveillance of the Manufacturing Process
- Assessment of a manufacturer's materials, production and control processes can,
at relatively low cost, provide assurance that the manufacturer's quality control
procedures are adequate. o Audit-Testing - In this procedure, test
samples are selected at random from the marketplace. Extensive testing is usually
required to provide adequate assurance that products meet the referenced standard. o
Field Investigations - Alleged failures of products during actual use are
investigated to determine the cause of failure and to suggest appropriate corrective
action. o Batch-testing - A sample of products is selected from a
production batch and tested for conformance to the standard. If the sampling procedure
and the sample size are adequate, batch-testing may be used to predict, with a
specified degree of confidence, that all products in that batch conform to the
standard. It does not, however, ensure that an untested product in the batch will
meet the standard nor does it furnish information on the quality of products produced
in earlier or subsequent batches. Batch testing is used in many certification
programs for building products. o 100 Percent Testing - In this
method, each individual product is tested to determine if it meets the designated
standard. If the testing procedures are adequate, the procedure provides the highest
possible level of assurance that the product conforms to a particular standard.
It is also usually the most expensive method and can be applied only where the
test has no adverse effect on the product. 14/ Many certification programs
rely on two or more of these methods for their approval process. The choice of
methods depends on the needs of both the buyer and the seller and on the nature
of the product. The chosen methods can greatly affect both the cost
of the program and the level of confidence that can be ascribed to it.
ANSI and ISO have each developed criteria to evaluate certification programs.
ANSI has also developed a program to accredit certification schemes which meet
its criteria. 15/ One of the criticisms of self-certification, namely that the
manufacturer does not have a third party checking the competence and integrity
of his results, fails to recognize that third party certification programs which
are not accredited also do not have anyone looking over their shoulder to ensure
the quality of their programs. 16/ Return to Contents
A mark of conformity or certification mark is
defined as "a sign or symbol owned or controlled by the certification body
that is used exclusively by the third-party certification program to identify
products or services as being certified and is registered as a certification mark
[when used in the United States] with the U.S. Patent Office under the Trade Marks
Act of 1946." 17/ A certificate of conformity, on the other hand is
"A tag, label, nameplate, or document of specified form and contents, affixed
or otherwise directly associated with a product or service on delivery to the
buyer, attesting that the product or service is in conformity with the referenced
standards or specifications." 18/ Certification marks and certificates
of conformity should be used to indicate that all essential characteristics of
the product have been assessed. In cases where only one or several aspects of
the product have been evaluated, such as flammability or electrical safety, this
information should be conveyed in some manner to the buyer lest the mark mislead
the buyer into placing more reliance on the certification than is justified. To
the extent possible, the symbols used in connection with the certification mark
should be capable of being interpreted without further definition. The marks or
accompanying information should also indicate the identity of the certification
body and any relationship that the body may have to the manufacturer. In
addition, the certificate of conformity should contain information on: (1) the
lot, batch or other production information to allow traceability to the production
source and time of production; (2) the date when the certificate was issued; and
(3) the officer of the company responsible for its issuance. Labeling included
with the product should identify the producer, and contain information on the
product's name, type or model number and all instructions necessary for the correct
and safe use and maintenance of the product. Return to
Contents
While certification programs benefit
both the seller and buyer of a certified product, certification programs also
have the potential for misleading users and for other abuses. Some of the more
significant potential problems in certification programs include: 1.
The Use of Inspection/Testing/Certification as a Substitute for Improving the
Quality of the Product and the Manufacturing Process. As Deming
has pointed out, quality must be designed into the product and assured through
an effective and efficient manufacturing process. Inspection, testing, and certification
will provide information on whether the desired end result has been achieved,
but usually too late in the manufacturing process to improve the quality of the
inspected/tested products. 2. Lack of Appropriate Standards on Which
to Base the Certification. Standards may not exist which cover
all essential characteristics of the product necessary to ensure a given level
of quality or safety, or the standards may exist but not be readily available. 3.
Technical Deficiencies in the Standards. The introduction of new
technology and new products may be inhibited particularly when design (rather
than performance) standards are used for certification and there is no provision
to handle products which fall outside the scope of the standard. Standards may
also contain specifications that are unnecessary and not based on well documented
research or information, or the specifications may be inadequate to ensure an
acceptable level of product quality or safety. 4. Lack of Valid Reproducible
Test Methods. Test methods may not adequately measure essential
characteristics or specifications included in the standard with reproducible results,
or the cost of testing might be prohibitive. Sample size requirements may not
be sufficient to ensure adequate representation of the entire production line.
Adequate test equipment, maintenance and calibration equipment may be difficult
to procure or unavailable. Laboratory conditions (temperature, humidity, level
of dust particles, etc.) may also negatively influence the outcome of the test
results. 5. Lack of Technical and Financial Competency on the Part
of the Certifier, Testing or Inspection Organization. The certifier,
laboratory, and/or inspection agency may lack the necessary technical competence
and resources to properly use and maintain the test equipment, to conduct the
required inspection/ testing, and to evaluate the results. The organizations may
not have developed adequate written documentation on the certification requirements
and procedures or may not have kept adequate records on the testing/inspection
results. The certifier or testing/ inspection organization might have ties to
the manufacturer or other biases which might compromise the integrity of the results. 6.
Public Misperception Regarding Legal Responsibility for a Certified Product or
Service. Despite public perception and assumptions that certification
implies legal responsibility for the quality and/or safety of the product or service
certified by a third party, most certifiers are not willing to accept such responsibility.
Responsibility for this liability generally rests with the manufacturer. 7.
Lack of an Adequate Appeals System. Disagreements may occasionally
arise among parties participating in a certification program. Provision should
be made within a program for an impartial appeals mechanism to handle disagreements
that cannot otherwise be resolved. Procedural requirements should be in writing
with minimal limitations on the timing of appeals, and on who may file. 8.
Lack of Knowledge on the Part of Users of the Certification Scheme. Buyers
who rely on a certification scheme and who are not adequately informed as to the
purpose, scope, and technical limitations of the resultant certification may be
misled as to the value and degree of confidence that can be placed on the mark
or certificate of conformity. 9. Lack of Adequate Follow Up and Enforcement. Without
adequate means to ensure that any misuse of the certification mark or certificate
of conformity is dealt with efficiently and effectively, the mark's integrity
may be compromised. Successors to the early "chiselers" continue to
try to circumvent certification requirements. Steps must be taken to ensure that
only authorized products bear the mark and that certified products that are subsequently
found to be hazardous or to have quality defects are either recalled from the
marketplace or have their marks or certificates of conformity removed. 10.
Incompatibilities among National Certification Schemes. When national
certification schemes for the same product or group of products differ significantly,
the result can be the need for extensive retesting at considerable expense in
terms of both time and money. The potential barriers to trade which can result
from differences in national certification programs have been discussed earlier
in this paper. Return to Contents
Certification programs
are communication tools designed to reduce the cost of exchanging information
between buyer and seller. The quality of the information conveyed depends on both
the impartiality and competence of the certifier and the adequacy and appropriateness
of the standards against which the product is evaluated. Certification may result
in widespread buyer deception if the performance characteristics or test methods
contained in a standard are insufficient to assure adequate product performance
or if the buyer is misinformed as to the extent to which product characteristics
have been evaluated. The United States has some of the most intricate certification
schemes in the world. Federal, state, and local government certification activities
impact on almost every aspect of life in the United States. It is therefore important
for all buyers to understand the certification process and what particular marks
of conformity mean to enable them to assess the value of certification information
to make intelligent choices To Request information, please contact:
Office of Standards Services (OSS)
National Institute of Standards and
Technology
National Center for Standards Certification & Information
100
Bureau Drive, MS 2150
Gaithersburg, MD 20899-2150 For more information,
please visit the NCSCI web site at http://www.ts.nist.gov/ncsci
Return to Contents
1/
American National Standards Institute (ANSI), Z-34.1-1987: American National Standards
for Certification - Third-Party Certification Program, American National Standards
Institute, New York, New York, p. A-7. 2/ International Trade Administration
(ITA), The Tokyo Round Agreements: Technical Barriers to Trade - Volume 4, Dept.
of Commerce, Washington, D.C., September 1981, p. 4. 3/ G. J. Varoufakis,
Materials Testing in Classical Greece, Technical Specifications of the 4th Century
BC, Hellenic Organization for Standardization, Athens, Greece, 1983. 4/
John Perry, Story of Standards, Funk & Wagnalls Company, New York, New York,
1955, p. 28. 5/ "Roofing Products Face Stringent Tests Before Receiving
FM Approval: An Interview with William F. Maroni, Manager, Building Materials
Section," 1988 Factory Mutual Approved Products News, 2nd Quarter 1988, pp.
10-11. 6/ W. Edwards Deming, Out of the Crisis, Massachusetts Institute
of Technology, Cambridge, MA, 1986, p. 29. 7/ W. Edwards Deming, Out of
the Crisis, Massachusetts Institute of Technology, Cambridge, MA, 1986, p. 28. 8/
ANSI, p. A-7. 9/ Robert B. Toth, NBS SP 714 - Federal Government Certification
Programs for Products and Services, U.S. National Bureau of Standards, Washington,
D.C., 1986, p. 1. 10/ Technical Help to Exporters (THE), International Certification
and Approval Schemes, British Standards Institution, Milton Keynes, England, 1987,
pp. 12-15. 11/ Ibid., pp. 16-19. 12/ Ibid., pp. 32-35. 13/ International
Organization for Standardization (ISO), Guide 7, "Requirements for Standards
Suitable for Product Certification," ISO, Geneva, Switzerland, 1982, p. 1.
14/ Douglas B. Thomas, NVLAP Glossary of Terms for Laboratory Accreditation,
Product Certification and Standardization, U.S. National Bureau of Standards,
Washington, D.C. 1980, pg. 4. 15/ ANSI, Policy and Procedures & Manual
of Operations for Accreditation of Certification Program, ANSI, New York, NY,
1976. 16/ Foster C. Wilson, Certification in Operation, unpublished, December
1986, pg. 3. 17/ ANSI, Z-34.1, p. A-7. 18/ ANSI, Z-34.1, p.
A-8. (1) Under 16 CFR Part 13, misrepresentations of product quality are
regarded by the Federal Trade Commission as prohibited trade practices. Certification
programs provide some assurance that claims made regarding a product's conformance
to a particular standard are in fact valid. Return to Contents
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