Keystone State Testing, in Lower Paxton Township, Dauphin County, is one of two labs approved by Pennsylvania for the testing of medical marijuana. The lab ensures medication is safe for patients and correctly labeled. The lab will test the ratios of cannabidiol, or CBD – a non-intoxicating compound – and tetrahydrocannabinol, or THC, – that component that causes the high- and make sure they are correctly identified on the label. The temporary health department regulations on labs also requires they test for pesticides, solvents, moisture content, and other substances.