5. Calculation internal exposure
There are not just tools to calculate the external exposure, there are also tools that can estimate the concentrations of chemicals that will occur in human biological matrices (such as blood, urine, ...) after the substance ended up in the body via inhalation, dermal and / or oral route. For some parameters, there are very nice linear relationships between concentration in breathing air during the work shift and urinary concentrations in the after-the-work shift, while for other substances there are sometimes more complex relationships, or even none at all. A fairly recent and well documented model to estimate internal exposure is IndusChemFate (Jongeneelen and ten Berge 2011). The model can be downloaded as an Excelapplication on the Cefic website.
NBN EN 689:1995 Workplace atmospheres - Guidance for the assessment of exposure by inhalation to chemical agents for comparison with limit values and measurement strategy
IRSST Biological monitoring concentration convertor
IndusChemFate Tool van Jongeneelen and ten Berge, Presentation (Dutch) NVvA congress 2012
CEFIC LRI Toolbox
http://www.employment.belgium.be/ has a specific page on chemical agents (Dutch)