The Toxicology of Graphene Oxide - which comes in different sizes and shapes that affect toxicology- is not well understood. It may be fair to say "it probably isn't good" but given the studies I have seen - there are doses that would likely not have drastic -or even noticeable effects. Just like pretty much every toxin on the planet.
If you want people to believe its so toxic that any dose is life-altering or life threatening you would have to bring the proof - if for no other reason that there are very, very few substances that are going to have a dramatic effect in any dosage.