I am not a doctor, and none of what follows is medical advice! Consult your own doctor before using CBD.
I asked NuLeafNaturals for lab results on their CBD oil. As the lab report is marked with a copyright from the testing laboratory, I cannot republish it here but the figures are found below.
But in a nutshell—for 20 common solvents and six microbial contaminants—non detectable levels of any of them—tap water is nasty stuff by comparison.
Total CBD: 55 mg/ml @ 60.0 mg/g
Total THC: 1.91 mg/ml @ 2.1 mg/g
ND = not detectable