Certification for Dummies: How to Certify an IGU and Why You Should

By Margaret Webb

The Insulating Glass Certification Council-Insulating Glass Manufacturers Alliance (IGCC-IGMA) Certification Program for the American Society for Testing and Materials (ASTM) E 2190 standard was originally known as the Harmonized Insulating Glass Standard, or HIGS. The IGMA program was launched in February 2003, combined with the IGCC program four years later, and continues to evolve and grow. This program is incorporated as a 501 c 3, operating in the public interest with a balanced board of industry participation and public interest.

In this day of increasing stringency, if a manufacturer wants to participate in the National Fenestration Rating Council (NFRC) or the Energy Star program, they must certify their products, including the insulating glass unit (IGU). Certification provides assurance to customers, whether they are door and window manufacturers, building code officials, architects and specifiers or homebuyers, that the IGU product they are buying is designed to meet or exceed the applicable code or standard.


In simple terms, products are certified to the applicable standard by testing specimens, conducting on-going inspection of production facilities and testing samples periodically to ensure they conform to the standard, the certification program requirements and the manufacturer’s specifications.

The actual program administration and maintenance can be quite complex. Administration requires a variety of forms, determination of re-certification, noting changes in the product line configuration that require re-certification and which ones are considered equivalent, gas filling, maintenance of the program documents and database, and coordination of all the information.

The certification cycle typically consists of three areas, all under the mandate and coordination of an administrator:

• Manufacturers produce IGUs;

• Auditors inspect units to ensure conformity to the manufacturer’s specifications and program requirements at regular intervals; and

• Approved test laboratories ensure conformance to the applicable test standard.

The two most commonly used forms are the certification program application form and the certification program audit report. The application form provides the administrator with the company information as well as the specific product configuration to be certified such as type of connector, spacer, desiccant and sealant system plus, if applicable, gas content. Information on coatings and glazing is also requested under the IGMA certification program. This information is entered into the audit report form and sent to the designated field auditor who will witness the fabrication of test specimens. For an existing certified product, the audit form contains this information as well as information recorded during prior audits. The auditor compares the information from the program database to the manufacturer’s actual production to ensure program compliance. The auditor also verifies that the manufacturer is in compliance with the program’s quality-assurance requirements, which vary program to program. Under the IGCC-IGMA program, 16 of the 20 elements necessary for ISO 9001 certification are required.


A formal quality-assurance program gives manufacturers control over the supply chain, whether it is a receipt of materials, component testing, control of production processes, control of non-conforming product, inspection of final units or customer inquiries.

Certification programs require that test sample fabrication is witnessed by independent auditors prior to the actual physical testing at approved laboratories. For a facility audit, whether it’s a new or existing product undergoing re-certification, the auditor contacts the manufacturer to arrange a mutually convenient date and time. The manufacturer is responsible for packaging and shipping their test units to an approved laboratory. A copy of the completed audit form accompanies the test samples so the laboratory can verify that the samples received are those that were fabricated and witnessed by the auditor.

Under the ASTM E 2190 standard, 12 (minimum) fabricated test units are required. The auditor verifies that the test specimens are as required under section 5.0 of ASTM E 2190 and fully representative of the manufacturer’s standard production units with regard to design and construction.

The administrator receives and re-cords the information issued by the laboratory, such as initial acknowledgment of receipt of the test specimens, initial test reports recording dew points, data summary sheets and the final test report indicating whether the test units have passed or failed. These reports show testing results for the weather-cycling, high humidity, volatile fogging and (if applicable) percent-age of initial gas fill.


The test procedure takes 139 days to complete. An initial dew point determination is done on all units when first received. Test units undergoing initial fill certification are sampled after the initial dew point is determined. The remainder of the testing is conducted on eight of the 12 samples, selected at random. Six units are tested for initial high humidity for 14 days, followed by 63 days of weather cycling. Two different units undergo the volatile fogging box procedure. An intermediate dew point is determined at the end of these tests. The units then undergo a second exposure to high humidity for an additional 28 days. A final dew point is taken at the end of this cycle and a final gas content is also recorded for those units under the IGCC-IGMA certification program.

In the past couple of years, two new requirements have been added to the quality/testing program. Manufacturers are required to calculate the amount of desiccant used in their units, and test units must include four test samples with airspace materials such as grills, muntins, blinds, etc. Some changes are coming to the latter requirement once ASTM finalizes the requirements for airspace materials.

Once certified, unannounced periodic inspections are carried out to ensure the product’s continued compliance. For each product line, the administrator will compare the information recorded by the auditor against the product database. Changes in the plant contact person, change of component supplier or in the components are all recorded in the database.

IG product certification is a requirement for all IG fabricators, and fenestration manufacturers must use at least one certified IG in their products to qualify for IGMA membership. However, IGMA welcomes participation from all IG manufacturers regardless of their membership status.

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