The authors presented data of chemical analytic control of chlorine compounds level in workplace air of vinyl chloride and polyvinyl chloride production, and biomonitoring results of vinyl chloride and 1.2-dichloroethane metabolite - thiodiacetic acid urinary level in workers of this production. Findings are exceeded hygienic norms on maximal concentrations of 1.2-dichloroethane in a workshop for vinyl chloride production from 1.0 to 2.85 MACs and of vinyl chloride in a workshop for polyvinyl chloride production from 2.06 to 5.52 MACs. Urinary levels of thiodiacetic acid were assessed in workers of vinyl chloride and polyvinyl chloride production in dependence on occupation, length of service and post-contact time.