To compensate for the lack of occupational exposure values and toxicological data, as well as the limitations of current sampling techniques, a committee of experts proposed a control banding model for facilitating the selection of appropriate respiratory protection against the great diversity of infectious and non-infectious bioaerosols present in workplaces. Easy to use, the proposed model consists of the four risk groups used in biosafety (1. low risk for individuals and communities; 2. moderate risk for individuals, low for communities; 3. high risk for individuals, low for communities; 4. high risk for individuals and communities) and five exposure levels (very low, low, medium, high, very high). Data cross-tabulation is used to establish an assigned protection factor (APF) that occupational health and safety practitioners will take into account in choosing appropriate respiratory protective equipment.
|
|
Exposure level
|
|
1
Very low
(0 – 2)
|
2
Low
(2.5 – 5)
|
3
Medium
(5.5 – 7)
|
4
High
(7.5 – 9)
|
5
Very high
(9.5 - 10)
|
|
Risk group
|
1
|
None
|
10
|
10
|
10
|
25
|
|
2
|
None
|
10
|
10
|
25
|
501
|
|
3
|
None
|
10
|
25
|
501
|
1000
|
|
4
|
1000
|
1000
|
1000
|
1000
|
1000
|
1 The APF of 50 of the National Institute for Occupational Safety and Health (NIOSH) is equivalent to the APF of 100 in the Guide des appareils de protection respiratoire utilisés au Québec.
Validation
"Our model is qualitative and is based on control banding approaches applying to chemical pollutants and nanoparticles. It 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, legionellosis, or even what the literature suggests as a protection factor for workers in recycling plants or pig houses," explains biologist and occupational hygienist Jacques Lavoie of the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), the study's lead author.
Better protection
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.
The study entitled Development of a control banding method for selecting respiratory protection againstbioaerosolscan beconsulted free of charge at: http://www.irsst.qc.ca/media/documents/PubIRSST/R-804.pdf
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Source
Jacques Millette
Manager, Public Affairs
IRSST
514 288-1551 ext. 210
The translation of this study into English was undertaken in response to a request from, and thanks to funding by, the CSA Group.
