Modeling of gaseous pollutant emissions following a battery failure event: occupational exposure estimation for a mining scenario
Keywords:inhalation exposure, probabilistic model, exposure modeling, mass-balance model, occupational exposure
The present study describes the implementation of a probabilistic Near-Field/Far-Field model based on the "Two-Box Model with a constant emission rate", applied for the characterization of a selected scenario. The aim was to describe the chemical agents (i.e., HF, HCl, H2SO4, Al, Ni) potentially emitted after a severe failure (i.e., thermal runaway event) of a Sodium/Metal Chloride battery during service in a simulated mining scenario. Risk management procedures are expected to be already implemented in the considered scenario; nevertheless, the use of a probabilistic approach for risk assessment indicated the presence of a certain level of risk in those scenarios (which could be however reduced by further implementing risk management procedures). More in detail, considering hazard quotients (HQ) calculated based on the far-field 95th percentile of estimated concentrations, the predicted exposure risk can be considered well-controlled in all the considered scenario, since all the HQ values calculated for the considered pollutants are stably below 0.1 of the respective OELV (both 8-h-TWA and 15-min -TWA OELVs), as well as the resulting Hazard Index (HI) for cumulative exposure. Contrariwise, when considering near-field estimated exposures, HQ values for Ni and HCl are above 0.1 (estimated exposure above 1/10 of the OELV) and 1 (estimated exposure above the OELV), respectively, thus indicating that the predicted exposure risk cannot be considered well-controlled in all considered scenarios for both Ni and HCl. Estimated near-field concentrations of HF, H2SO4 and Al resulted in HQ below 0.1, thus the predicted exposure risk can be considered well-controlled in all the considered scenario for these pollutants.
Cattaneo, A., Spinazzè, A., & Cavallo, D. M. 2018. Occupational exposure limit values for chemical risk assessment at European level. Ital. J. Occup. Environ. Hyg., 9, 93-97.
FIAMM - Technical report. 2012- Environmental assessment of exposure to gas emissions following a severe failure - Abuse testing (internal short circuit) on a full battery pack. - Revision: 08/05/2012
Ganser G.H., Hewett P. 2017. Models for nearly every occasion: Part II - Two box models. J Occup Environ Hyg.;14(1):58-71. doi: 10.1080/15459624.2016.1213393. (Erratum in: J Occup Environ Hyg. 2017;14(8): D139).
Hewett, P., Logan, P., Mulhausen, J., Ramachandran, G., Banerjee, S. 2006. Rating Exposure Control Using Bayesian Decision Analysis. J. Occup. Environ. Hyg. 3(10): 568–581. doi: 10.1080/15459620600914641.
Koivisto, A.J., Spinazzè, A., Verdonck, F., Borghi, F., Löndahl, J., Koponen, I.K., Verpaele, S., Jayjock, M., Hussein, T., Lopez de Ipiña, J., Arnold, S., Furxhi, I. 2021. Assessment of exposure determinants and exposure levels by using stationary concentration measurements and a probabilistic near-field/far-field exposure model [version 1; peer review: 2 approved]. Open Research Europe, 1:72. doi: 10.12688/openreseurope.13752.1.
Nicas, M. The Near Field/Far Field (Two-Box) Model with a constant contaminant emission rate. In “Mathematical Models for Estimating Occupational Exposure to Chemicals”, 2nd Edition, 2009. Edited by Charles B. Keil, Catherine E. Simmons, and T. Renee Anthony. AIHA, Farifax, VA (USA). ISBN: 978-1-935082-10-1
Polvara, E., Spinazzè, A., Invernizzi, M., Cattaneo, A., Sironi, S., Cavallo, D. M. 2021. Toxicological assessment method for evaluating the occupational risk of dynamic olfactometry assessors. Regul. Toxicol. Pharmacol, 125, 105003.
Spinazzè, A., Borghi, F., Cattaneo, A., Cavallo, D.M. 2020. Control banding tools and exposure estimation models for occupational chemical risk assessment. Ital. J. Occup. Environ. Hyg., 11(1):47-51. Doi: 10.36125/ijoehy.v11i1.338