In May EPA published an official classification that glyphosate was "not likely" to be carcinogenic to humans.
The Scientific Advisory Panel (SAP) review is viewed as EPA's effort to "cover all of its bases" on its assessment on the herbicide.
The assessment contradicts findings by the International Agency for Research on Cancer, which claimed the opposite was the case in a review last year.
Last November the European Food Safety Authority (EFSA) echoed EPA and found that glyphosate was "unlikely to pose a carcinogenic hazard to humans".
EPA was meant to turn over its findings to the SAP in October, but concerns from the pesticide industry over potential scientific biases led to a delay while panel membership was changed.
The panel meets in Arlington, Virginia, and Tuesday will be dominated by EPA presenting its findings and methodology. That will be followed by public comments on Wednesday.
Glyphosate is up for re-registration in the EU and the EC has recommended a seven-year extension, but not for retail or amenity sales.
Monsanto markets glyphosate-based Roundup and chief executive Hugh Grant said after the initial EPA announcement in May no pesticide regulator in the world saw glyphosate as a carcinogen.
Glyphosate had a 40-year history of safe and effective use, but last year’s classification by IARC generated "unwarranted concern and confusion", he said.