You've stated that ETG is not cumulative but then answered people's questons if it was with this answer "EtG is a by-product of alcohol metabolism. It is dose dependent. One drink creates a small amount of EtG, 20 drinks create a lot of EtG. EtG is eliminated at a steady rate". Is is cumulative or not? Explain additive vs. Cumulative to me. Thanks

EtG/EtS does not store in body tissue. Rather it follows a pattern of continuing steady elimination. Just like alcohol (EtOH) it will add up only when consumption exceeds the rate of elimination. That is the basis of BAC. But once you stop drinking then all of the alcohol, 100%, will eliminate at a steady rate and none remains.

As a comparison, the marijuana metabolite THC is prone to store in fatty tissue. As more and more is taken in a portion is not metabolized and accumulates. Over a period, even after the individual hasn't smoked in a significant time span there is still measurable THC in their system.

Not so with EtOH or metabolites. It adds up while you are drinking only because you are pouring it in faster the body can process it. Increasing amounts of systemic EtOH creates increasing amounts of EtG in proportion to the amount of EtOH consumed and the rate of consumption (dose dependent).

At last review there are only two studies relating to this phenomenon (EtG), listed below.

Sarkola, 2003 (most referenced)
Rosano & Lin, 2008, p. 597