Is the Cobb Test necessary for UN Certification?
Yes. As per 178.516 of CFR 49 (Standards for Fiberboard Boxes) the water resistance of the outer surface must be such that the increase in mass is not greater than 155 g per square meter over a 30 minute time period. NOTE: Pro-Pack Testing Laboratory does not have to perform this test as long as the following information is provided from the supplier of the corrugated material: A letter on company letterhead showing 30 minute Cobb Test results on COMBINED board as well as materials analysis results on the corrugated that the Cobb Test was performed on.
