So obviously with these additives being pointed out as harmful, many eliquid and concentrate manufactures have been releasing independent lab reports showing concentrations. The concentrate vendor I use most often is Capella, and a vast amount of their concentrates have certification to be free of these additives, or more precisely for them all to be under 5ppm, or under 0.0005%. Is there any info on what levels are acceptable, or is the only clear cut answer 0ppm i.e. 0.0000%?