RE:More damning studies on graphene. ZEN needs to move past mak A quote from https://onlinelibrary.wiley.com/doi/full/10.1002/advs.201903200
"In respect to the pulmonary route of exposure, graphene nanoplatelets (GNPs) have been the most widely studied GBMs to date, with several reports of transient inflammation after pulmonary exposure.[8-14] In addition, Roberts et al. demonstrated that GNPs with large lateral dimensions (5–20 µm) have a more detrimental impact on the lungs than their smaller counterparts (<2 µm) following oropharyngeal aspiration,[15] supporting the view that dimensions of these materials are a major determinant of their pulmonary toxicity. However, despite evidence that GNPs may persist in the lungs without being inflammogenic even after 6 weeks,[16] longer term consequences of material persistence in the alveolar region, such as late onset disease or carcinogenesis, remain largely unknown."
All of Zen's GO products fall in the 1-3 µm size range. Would they have sourced and experimented with another producer's GO at another flake size... maybe, but I doubt it.