A committee of experts from the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) have proposed a control banding model for facilitating the selection of appropriate respiratory protection against aerosols.
The model is used to compensate for the lack of occupational exposure values and toxicological data, as well as the limitations of current sampling techniques, said IRSST.
The proposed model consists of the four risk groups used in biosafety:
• low risk for individuals and communities
• moderate risk for individuals, low for communities
• high risk for individuals, low for communities
• high risk for individuals and communities.
It also looks at five exposure levels (very low, low, medium, high, very high).
A model like this is important to protect against the great diversity of infectious and non-infectious bioaerosols present in workplaces, said IRSST.
By cross-tabulating data, an assigned protection factor (APF) can be determined to help OHS practitioners select the appropriate respiratory protective equipment.
This model, which is based on control banding approaches applying to chemical pollutants and nanoparticles, has been validated by case studies that involve comparing the model’s proposed protection factors with existing recommendations for various risks, such as SARS, tuberculosis, anthrax and legionellosis, said IRSST.
Control banding is a technique used to guide the assessment and management of workplace risks. This technique is used to match a control measure (such as ventilation, engineering controls, containment and PPE) to a range or "band" of hazards and exposures (such as skin/eye irritation, very toxic or carcinogenic). It was originally developed by the pharmaceutical industry as a way to work safely with new chemicals that had little or no toxicity information.
While it requires a certain level of knowledge and cannot be used for environmental monitoring, control banding allows practitioners to focus their efforts on the choice of control strategies rather than on measuring bioaerosol exposure. According to the researchers, this approach, which will be improved and more widely used, increases worker protection and reduces the effects of contaminants on workers' health.