Exposure to infectious and crystalline respirable agents : Take measures or following-up option?

by Nov 19, 2019Hazardous materials

No Workplace is immune from biological hazards. Employees in different types of work may be intentionally or accidentally exposed to biological agents (Haagsma et al. 2012). These include parasites, viruses, bacteria, fungi and protein. They can appear and disappear due to a variety of factors (J. F. Shroder and Ramesh Sivanpillai, 2015), so it is important for workers to be prepared for.


« A biological hazard is an organism or substances produced that may pose a threat or any harm to human health, to people, even animals or vegetables matrerials individually and able to spread from one living being to another. »


In the same way, any of them could be considered as a biological hazard as soon as they can contaminate or pose a health risk.


Transmission ways are numerous

In general, there are three major ways of entry of these micro-organisms to enter our body: through the respiratory system, through contact with body fluids of the infected by transmission or contact with contaminated objects. Then, the risk of biological hazards may also vary depending on the mode of transmission or the area of ​​the body affected.

For example, recent studies continue to confirm that long-range transmission of cold/influenza is possible via aerosols in the respirable size range. Inhalation of silica particles can also cause other lung diseases such as chronic bronchitis and cancer (CNESST, 2012). Birds droppings such as pigeons transmit histoplasmosis, a disease which manifests as a flu or cryptococcosis with dispersion of spores in the air (Canada, 2013). Manganism is the consequence of exposure to manganese (fine crystalline particle) after inhalation or via water or food in occupational areas like mining, welding, iron/steel making, ferro/silico-Mn alloy and dry alkaline battery production (Lucchini et al., 2015). Transmission of some viruses may occur by touching contaminated surfaces or objects, or touching the unprotected eyes, nose, or mouth. Beyond them, proximity is still the first case as a major factor in respiratory disease transmission. Exposure of these body’s parts to airborne viruses may cause other forms of diseases.


Now, without wanting to deepen the contamination ways by these pathogens agents, this blog is particularly is interested in respiratory contamination. This, because of the huge use of respirator masks and scientific recommendation for public health and workplace prevention


Always elimination at the source

Engineering controls such as improvement of ventilation, partial isolation of the contamination source, installation of negative pressure and separate ventilation and air conditioning system and the use of ultraviolet lamps can help contain the spread of contaminants.

But, if the contact with biological hazards cannot be prevented or mode of transmission can’t be mastered, personal protective equipment and personal hygiene are still the best protection.


Respirator mask: A must!

Respiratory protection are important devices for protection when infectious biological aerosols are potentially present in a workplace with engineering controls to respect elimination at the source. The use of respiratory devices against potentially hazardous biological agents that are transmittable via inhalation has increased in recent years (Janssen et al. 2013). When in an environment containing this potential hazard, dust and other hazard like crystalline respirable particles (silica, etc.), both surgical masks and filtering facepiece respirators (N95, SM, 3M, etc.) have been used by the public as well as health care workers and industrial workers. There are different types depending on the type of protection sought, le type of biological hazard, the nature of work and the environment: surgical masks, N95 or higher-level respirators, Powered Air Purifying Respirator (PAPR), Chemical Cartridge, Air-supplying respirators and so on. It’s important to choose the appropriate respiratory protective equipment and to wear it properly!


When your mask is it effective?

According to NIOSH (2012) respiratory protection is effective only if:

  • the mask is used correctly,
  • it’s available when you need it,
  • you know when and you are trained to put it on and take it off, and
  • you have stored it and kept it in accordance with the manufacturer’s instructions

According to these facts in Quebec, operations running in any workplaces containing infectious agents or high concentrations of bioaerosols or high probability of their presence, a respiratory protection (from basic to the most specialized) is required. The sections 41 to 47 of the RSST must be respected.


However, there are gloves, protective clothing, safety glasses / faceshields, boots, raincoats specifically designed to complete the protection and to withstand microorganism’s penetration at work (OSHC, 2003; RSPST).


Exposure limits values: Measures and Following-up

The answer is here!

Since you identified infectious biological strains at your workplace, it is important to know the exposure limits that should not be reached and the monitoring measures to follow their development (or not) and the safety recommendations. In this way many instruments have been developed : measure toxic gases / vapors and microorganisms in the environment.

So, knowing human dose-response for some respiratory pathogens, helps to estimate the infectious level not to be reached. In Quebec currently, the regulation respecting occupational health and safety establishes the average exposure value for many elements like silica (0.1 mg /m3 for a period of 8 hours / day, over 40 hours of work). This is the reason why to improve the infectious biological risks assessment, organizations like ACGIH, CNESST and others, publish and update exposure limits for biological particles in workplaces to help prevention.

In addition unfortunately, today as said Schulte and HeeKyoung (2009) global climate change is making some areas more favourable to some pathogens where the conditions previously considered impossible. We agree with Émilien Schultz (2019) on the fact that threshold values for toxicity are not enough to stop various contaminations that humans face nowadays


In conclusion, organizations can’t avoid exposure limits leagacy, but may associate it to rigorous following-up. Because, monitoring is the sustainable management strategy for any workplace for better strategies to maintain the safety margin not to exceed in relation to the exposure limits values specified for biological hazards.


However, Intervention Prevention by mapping every disease based on biological, electrical, mechanical and operational criteria in your workplace, could make an inventory of your worker’s expositions.

Tell us about your needs and an expert will answer you!

Intervention Prévention Inc.

Intervention Prévention concentrates its operations in the field of work safety, offering specialized services following Standards CSA Z462 – Workplace Electrical Safety, CSA Z460 – Control of Hazardous Energy: Lock-out and Other Methods, and CSA Z432 – Safeguarding of Machinery.


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