BioProtect Tool: a Control Banding Method for Respirator Selection against Bioaerosols
Eve Neesham-Grenon, Jacques Lavoie, Yves Cloutier, Genevieve Marchand, and Maximilien Debia
Selecting the right respirator to protect workers against occupational exposure to bioaerosols is complicated by the lack of occupational exposure limits, the limits of current sampling methods, the diversity of bioaerosols and the inconsistency among experts’ recommendations. Thus, qualitative methods such as control banding offer a more practical alternative for risk assessment and management of bioaerosols. The objective of this project was to develop a control banding approach, the BioProtect
Tool, for respirator selection against both infectious and non-infectious bioaerosols applicable to all workplaces. A committee including occupational hygienists, microbiologists and physicians, as well as experts in the fields of control banding, respiratory protection, ventilation and aerosol physics was formed to develop and validate the model. A 4 x 5 selection matrix was developed, with four biosafety risk groups and five exposure level bands. Each exposure level band is the sum of a control level band and a generation rate band. A minimum protection factor is assigned to each risk group-exposure level pair, allowing the user to identify an appropriate respirator. A validation of the model using nineteen case studies showed that the assigned protection factors obtained with the control banding approach matched or exceeded the assigned protection factors retrieved from the literature in fifteen cases out of nineteen. Comparison with the Canadian Standard Association’s control banding model also showed that the control banding approach presented in this publication is more sensitive to slight changes in workplace conditions and tends to give more conservative results. Overall, the control banding approach developed is a simple and useful tool for assessing the risk of occupational exposure to infectious and non-infectious bioaerosols, providing recommendations for respirator selection and identifying activities that present the most risk. It could be easily integrated into the assessment and management of occupational risks wherever workers are exposed to bioaerosols.
Keywords: Control banding, bioaerosols, respiratory protection, risk assessment