Does a product containing 0 g/L VOC still need emissions testing?

yes, unless it is inherrently non-emitting. 

Gretchen, I agree with Dave. The reason is that (as I understand it) there are allowable exclusions when manufacturer's calculate the VOC content (g/L) using the EPA Reference Method 24. So a product with "Zero VOC" content may actually contain VOCs, which would show up in emissions testing.

Hi Gretchen,  Yes, agree with Dave.
LEED guide states, products that are inherently nonemitting sources of VOCs (stone, ceramic, powder-coated metals, plated or anodized metal, glass, concrete, clay brick, and unfinished or untreated solid wood flooring) are considered fully compliant without any VOC emissions testing if they do not include integral organic based surface coatings, binders, or sealants. USGBC recognizes that such products do not need to undergo testing to prove they do not emit VOCs. Best regard – Afogreen Build Team