Why is Germany tolerating Russian chemical weapons facilities on its soil?

Why is Germany tolerating the presence on its soil of elements of Vladimir Putin's chemical weapons program?

The question arises in light of new sanctions introduced against Russia on Tuesday, in response to its August 2020 chemical weapons attack on opposition leader Alexei Navalny. Those sanctioned include three German companies, now added to the U.S. government's so-called "Entity List." Those on the "Entity List" face increased restrictions or even bans from U.S. exports. The newly proscribed German companies, Chimconnect, Pharmcontract, and RIOL-Chemie, were cited for their support of Russia's chemical weapons program.