The Soviet Union had a vast store of chemical weapons - in particular nerve agents ,persistent, to deny the use of facilities such as airfields and logistics facilities on a long term basis, and non persistent nerve and blood agents to kill large numbers of unprotected troops and civilians quickly. A significant proportion of their artillery, ammunition had chemical filling, and Soviet doctrine regarded it as simply another option along with high explosive and other fillings and fuzing options. Soviet doctrine was to use chemical weapons well before nuclear ones.
The Russians retained, and have brought out of storage to use, much of the materiel and equipments from that era, tanks, armoured vehicles, (which were designed to be used on a chemical battlefield), along with the traditional artillery (122mm and 152mm calibre) and rocket systems that would deliver it.
It is no stretch at all to imagine, in fact I would say that it is almost certain, that they retain the munitions, and would be prepared to use them.
It is "low tech", requires relatively little training to use (if you can load a high explosive shell you can load a chemical one) and fire it.