What Is It?
IGMA is short for the Insulating Glass Manufacturers Alliance and its certification program requires manufacturers of insulating glass to meet quality control standards and the Canadian General Standards Board edge seal standard (CGSB 12.8/ASTM E 2188/ASTM E 2189/ASTM E 2190). This particular certification program applies to the glazed unit only.
What to Look For?
All IGMA-certified products carry the IGMA or IGMAC logo as well as the date and place of manufacture and the company name.
Where to Find It?
This information is usually stamped on the spacer or etched onto the glass.