2022/12/18 by Nasterlack, Michael, Drexler, Hans, Hartwig, Andrea +1
#Arbeitsstoff #Biomonitoring #Chlorethen #Chlorethylen #Chloroethene #Chloroethylene #EKA #Expositionsäquivalente für krebserzeugende Arbeitsstoffe #Gefahrstoff #Monochlorethen #Monochlorethene #Monochlorethylen #Monochloroethylene #TdAA #Thiodiacetic acid #Thiodiessigsäure #Thiodiglycolic acid #Thiodiglykolsäure #Toxizität #Urin #Vinyl chloride #Vinylchlorid #biomonitoring #exposure equivalents for carcinogenic substances #hazardous substance #occupational exposure #toxicity #urine
paper · doi:10.34865/bb7501e7_4ad
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated in 1989, and confirmed in 2009, the exposure equivalents for carcinogenic substances (EKA) between inhalation exposure to vinyl chloride [75-01-4] monomer and urinary excretion of its main metabolite, thiodiglycolic acid (thiodiacetic acid, TdAA). It was based on a study that found a statistically significant correlation between the total excretion of TdAA over 24 hours following the start of a workshift and the time-weighted average of vinyl chloride exposure during this shift. This definition, however, required the collection of 24-hour urine samples and turned out to be limited in its applicability both for logistic and practical reasons. The Commission therefore examined the option to translate the values based on total TdAA excretion into TdAA concentrations expected in spot urine samples. A literature search, however, confirmed that vinyl chloride uptake, metabolism and excretion are influenced to a large extent by both individual (body mass, body fat content) and exposure characteristics (intensity and time course of vinyl chloride exposure), resulting in considerable variation of the peak of TdAA excretion after the end of exposure. Given that this time window extended over at least 36 hours, it was impossible to define an appropriate sampling time to allow for meaningful and representative results. This led to the conclusion that EKA cannot be established with a sufficient degree of reliability. Therefore, the EKA are withdrawn.