Addendum to arsenic and inorganic arsenic compounds (with the exception of arsine).

he German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the “Biologischer Arbeitsstoff‐Referenzwert” (BAR) as well as the exposure equivalents for carcinogenic substances (EKA) for arsenic and inorganic arsenic compounds (with the exception of arsenic hydride). Available publications are described in detail. The quantification of the various arsenic species is essential to understand the hazardous potential of the arsenic compounds which differ highly in their toxicity. Therefore the BAR for the sum of different arsenic species is no longer valid. Considering published data from occupational not exposed persons, new BAR for the arsenic species of 0.5 µg/l urine for arsenic (+III), 0.5 µg/l urine for arsenic (+V), 2 µg/l urine for monomethylarsonic acid (MMA) and 10 µg/l urine for dimethylarsinic acid (DMA) were evaluated. The differentiation of arsenic species now allows for the estimation of the individual health risks taking into account special influences like seafood consumption. Sampling time is at the end of exposure or the end of the working shift and after long term exposure at the end of the working shift after several shifts. Data of a correlation of arsenic in the air and the sum of the arsenic species in urine were considered for the evaluation of the exposure equivalents for carcinogenic substances. This correlation is in good accordance with the EKA correlation of arsenic trioxide, which is based on former studies in which also the urinary concentrations of the sum of As (+III), As (+V), MMA and DMA were measured. Sampling time is at the end of exposure or the end of the working shift and after long term exposure at the end of the working shift after several shifts

Dichlormethan, Addendum [BAT Value Documentation in German language, 2016]

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated dichloromethane, considering dichloromethane in blood to characterize the internal exposure. In a chamber study, 14 non‐smokers were exposed to different concentrations of dichloromethane. After exposure to the present MAK‐value of 50 ml dichloromethane/m3 without physical activity, a concentration of 0.3 mg dichloromethane/l blood was measured. Considering an increased intake due to elevated breathing volume during work, the exposure to 50 ml dichloromethane/m3 results in a blood concentration of 0.5 mg/l. Taking into account this study and the EKA correlation of 2001, a BAT‐value of 500 µg dichloromethane/l blood was evaluated. Sampling time is straight after exposure

Tri‐n‐butyl phosphate [BAT Value Documentation, 2018]

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area evaluated tri‐n‐butyl phosphate [CAS No.126‐73‐8] in 2016 and derived a biological reference value (“Biologischer Arbeitsstoff‐Referenzwert”, BAR) for dibutyl phosphate in urine. Available publications are described in detail. In a study with persons of the general population occupationally not exposed to tri‐n‐butyl phosphate a 95th percentile of 0.67 µg dibutyl phosphate/l urine was measured. Further studies with non‐exposed individuals resulted in maximum levels of 0.45 µg and 0.26 µg dibutyl phosphate/l urine. Taking these results together with other investigations into consideration, a BAR for tri‐n‐butyl phosphate of 0.5 µg dibutyl phosphate/l urine was established. Sampling time is at the end of exposure or the end of the working shift