Suchergebnisse

Abstract
According to good occupational hygiene practices, measurement uncertainty (U) should be included when testing TWA workplace atmosphere measurement against OEL.
In some countries such as the US (OSHA) and Belgium, this is included in legislation: law enforcement tests the TWA lower confidence limit LCL=TWA*(1-U) exceedance of the OEL while employers test the TWA upper confidence limit UCL=TWA*(1+U) compliance with the OEL.
International standards such as EN482 and ISO-20581 help establish U, UCL and LCL.
Current exposure assessment strategies promoted by IOHA members, such as AIHA (2015), EN689 (2018) and BOSH/NVvA (2022), ignore measurement uncertainty.
This may be due to historical work (Nicas, 1991), which shows that in similar exposure groups (SEG), lognormal long-term daily environmental variability exceeds U.
However, Monte-Carlo simulations, which will be shown in this lecture, show that the influence of U on the lognormal, one-sided upper confidence limit of the 95th percentile (UTL95,##%) can be significant in occupational hygiene practice with sample sizes often smaller than n=6.
Also in the last decade, several strategies promote a simplified screening/preliminary test (French Code du Travail, EN689:2018 §5.5.2, BOSH/NVvA 2011/2022).
In these tests, the highest result (TWAmax) of 3 to 5 measurements is compared with the OEL or with a defined fraction f(OEL).
In line with the above, these TWAmax tests should use TWAmax*(1-U) ≤ f(OEL) for compliance and TWAmax*(1+U) > OEL for exceedance.
IOHA member organisations are advised not only to align the numerical test schedules for compliance, but also to include measurement uncertainty in the OEL tests.

Abstract
The purpose of these two consecutive IOHA exposure assessment PDC's is to train assessors in broad accepted strategies and in the assumptions, use and differences of supporting apps and tools.
Part I works with the EN 689 (2018), BOHS-NVvA (2011/22) and AIHA (ed. 4; 2015) strategies and the high-quality apps supportive for a reproducible basic characterisation of exposure profiles, including exposure range finding, need for direct controls or Similar Exposure Group (SEG) formation and sampling.
Tools and instruments like AIHA IHEST and EN689 Annex A support a professional basic characterisation. To distinguish between safe, unsafe and profiles to be monitored, exposure modelling apps exist like AIHA IHMOD and several hybrid models collected in the TREXMO hub (i.e. ECETOC TRA, Stoffenmanager, ART). When sampling is performed the Excel application IH-Aligner helps to convert lab results to TWA (=time-weighted average) exposure levels in accordance with the reference period of the Occupational Exposure Limit Values (OELV). Measurement uncertainty-based confidence intervals are constructed for the individual outcome and to perform individual and small sample screening comparison with the OELV. IH-Aligner automatically prepares worksheets with the TWA exposure values for direct export to several recognized compliance testing apps which will be trained in Part II of the PDC.
Participants need to bring their own laptop with Windows OS, the software installed and the links to the online apps. Participants will receive in advance IH-Aligner, links to download the other apps, instructions and example data sets. If time permits, exposure profiles datasets of participants will be discussed.

Hazard Banding (HB) is a process of allocating chemical substances in bands of increasing health hazard based on their hazard classifications. Recent Control Banding (CB) tools use the classifications of the United Nations Global Harmonized System (UN GHS) or the European Union Classifications, Labelling and Packaging (EU CLP) which are grouped over 5 HBs. The use of CB is growing worldwide for the risk control of substances without an Occupational Exposure Limit Value (OELV). Well-known CB-tools like HSE-COSHH Essentials, BAuA-Einfaches Maßnahmenkonzept Gefahrstoffe (EMKG), and DGUV-IFA-Spaltenmodell (IFA) use however different GHS/CLP groupings which may lead to dissimilar HBs and control regimes for individual substances. And as the choice for a CB tool seems to be determined by geography and/or local status these differences may hamper a global, aligned HSE approach. Therefore, the HB-engines of the three public CBs and an in-company (Solvay) CB called 'Occupational Exposure Banding' (S-OEB) were compared mutually and ranked in their relation with the OELV as the 'de facto' standard. This was investigated graphically and using a 5 strength indicator, statistical method. A data set of 229 substances with high-quality GHS/CLP classifications and OELVs was used. HB concentration ranges, as linked to S-OEB and COSHH, were validated against the corresponding OELV distributions. The four HB-engines allocate between 23 and 64% of the 229 substances in the same bands. The remaining substances differ at least one band, with IFA placing more substances in a higher hazard band, EMKG doing the opposite and COSHH and S-OEB in between. The overall strength scores of S-OEB, IFA, and EMGK HB-engines are higher than COSHH, with S-OEB having the highest overall strength score. The lower ends of the concentration ranges defined for the 3 'highest' hazard bands of S-OEB were in good agreement with the 10th percentiles of the corresponding OELV distributions obtained from the substance data set. The lower ends of the COSHH ...

Hazard Banding (HB) is a process of allocating chemical substances in bands of increasing health hazard based on their hazard classifications. Recent Control Banding (CB) tools use the classifications of the United Nations Global Harmonized System (UN GHS) or the European Union Classifications, Labelling and Packaging (EU CLP) which are grouped over 5 HBs. The use of CB is growing worldwide for the risk control of substances without an Occupational Exposure Limit Value (OELV). Well-known CB-tools like HSE-COSHH Essentials, BAuA-Einfaches Maßnahmenkonzept Gefahrstoffe (EMKG), and DGUV-IFA-Spaltenmodell (IFA) use however different GHS/CLP groupings which may lead to dissimilar HBs and control regimes for individual substances. And as the choice for a CB tool seems to be determined by geography and/or local status these differences may hamper a global, aligned HSE approach. Therefore, the HB-engines of the three public CBs and an in-company (Solvay) CB called 'Occupational Exposure Banding' (S-OEB) were compared mutually and ranked in their relation with the OELV as the 'de facto' standard. This was investigated graphically and using a 5 strength indicator, statistical method. A data set of 229 substances with high-quality GHS/CLP classifications and OELVs was used. HB concentration ranges, as linked to S-OEB and COSHH, were validated against the corresponding OELV distributions. The four HB-engines allocate between 23 and 64% of the 229 substances in the same bands. The remaining substances differ at least one band, with IFA placing more substances in a higher hazard band, EMKG doing the opposite and COSHH and S-OEB in between. The overall strength scores of S-OEB, IFA, and EMGK HB-engines are higher than COSHH, with S-OEB having the highest overall strength score. The lower ends of the concentration ranges defined for the 3 'highest' hazard bands of S-OEB were in good agreement with the 10(th) percentiles of the corresponding OELV distributions obtained from the substance data set. The lower ends of the COSHH ...