When Zero doesn't really mean Zero

The EPA has determined that the off-gassing from architectural coatings is estimated to account for about 9% of the VOC emissions from all consumer and commercial products. It is important to understand that the EPA’s test method for VOC’s, any paint with VOC’s  5 g/l or less can be called zero VOC so even paint labeled zero VOC may not actually be truly zero VOC.

 Now I know that 5 g/l is very low in the big picture and I may be nitpicking but I was always taught that 0=0,  not 0=5 or less