COVID-19 causes dust mask shortages

The world awaits a vaccine for COVID-19 coronavirus, but in the meantime many people are choosing to protect themselves from infection by purchasing dust masks and respirators, leading to chronic shortages of supply. But do all masks protect against viruses? And are tradespeople able to get sufficient supplies? John Power reports.

Walk down any major city street these days and it is easy to spot pedestrians wearing facial masks.

Indeed, demand for facial masks – which have almost become a fashion accessory in some circles – has become so high that many hardware stores are running out of popular lines; ‘Out of Stock’ notices in stores and online testify to the escalating rates of panic purchases, as do the seemingly arbitrary selections of products according to price rather than fitness for purpose. Unsurprisingly, complaints of price gouging have gone hand-in-glove with this unprecedented demand.

In this context, it is worth examining the world of facial masks and respirators to see how product lines differ, and to consider how shortages of supply might be affecting workers in hazardous environments involving dust and harmful gases.

First, let us take a look at common masks.

Different types of masks

The most common mask seen in public is a surgical mask. Though not designed for use as a dust mask, these (typically) rectangular, single-tie coverings over the mouth and nose are designed for medical staff in direct healthcare settings.

These masks are not tightly fitting, and therefore allow some air to pass around the edges, which means they do NOT offer meaningful protection against the inhalation of fine particles carrying viruses or bacteria. 

Rather than stop the wearer from becoming infected with a pathogen, these masks are designed to stop the wearer from infecting other people through coughs or sneezes.

Widespread use of surgical masks first appeared in Japan, where workers who were unwell opted to wear a face covering as a courtesy to colleagues, i.e. as a gesture to show they were attempting to stop their disease from spreading to others. Subsequently, people in urban environments in China and India, for instance, adopted the use of masks in the hope that they might help purify polluted air.

By contrast, a genuinely effective mask designed to prevent infection from COVID-19 (and other airborne viruses or bacteria) is commonly known as a particulate respirator.

These kinds of disposable respirators are designed to filter out harmful particles down to approximately 0.3 microns in size.

Within this class of respirator there are multiple subsets, including N-95, N-99, N-100, R-95, R-99, R-100, P-95, P-99, and P-100.

The letter ‘N’ stands for ‘Not resistant to oil’, ‘R’ designates Resistant to oil, and ‘P’ means oil-proof.

Given that most public airborne diseases are carried in a non-oil environment, the ‘N’ class of respirators is adequate for typical applications in hospitals or in public places.

The numbers ‘95’, ‘99’, and ‘100’ refer respectively to the percentage of effectiveness of the filter in worst-case scenarios. So, a standard ‘N-95’-rated respirator will catch 95 per cent of particles in a worst-case scenario in a non-oil environment, which is deemed satisfactory in most standard health-based settings.

If a wearer wants to enhance the level of protection, then they might pay to choose an N-99 or N-100 product. 

A quick digression: customers might see a different sort of rating system – P1, P2 or P3 – on product labels of disposable dust masks. This kind of quick classification system is very popular, with higher numbers indicating enhanced degrees of protection; of course, always check that the product actually performs to the required level of safety for the task at hand. Reputable brands of P2 or P3 dust masks, for instance, often feature a corresponding ‘N-95’-style reference somewhere on the packaging.

As mentioned, a quality disposable respirator can trap particles down to approximately 0.3 microns. But how can a respirator trap viruses, which are much smaller than 0.3 microns? (A common virus can be 0.125 microns or smaller in size.) Well, even though individual viral spheres are tiny, these spheres do not drift on the air like pollen; on the contrary, they are carried via larger particles of saliva, water, etc., and these larger particles can definitely be stopped by a typical N-95 mask… providing the mask has been fitted correctly, particularly around the nose area, to minimise air transference along the edges.

It is worth noting the particle sizes of other common contaminants: asbestos particles can range from 0.7 to 90 microns, mould spores can be 10-30 microns, and bacteria can be 0.3-60 microns. Airborne sawdust particles can be 30-600 microns.1 By contrast, a gas like CO2, which is not described as a ‘particle’ in the context of particulate respirators, might be 0.00065 microns, which is far smaller than a disposable respirator is designed to block. 

For greater protection than that afforded by a disposable mouth/nose respirator, there are more advanced, non-disposable respirators such as half-face and full-face units with their own replaceable filters for repeated applications, as well as gaskets for snug seals against the face. Designed for more dangerous situations, including chemical as well as particulate hazards, these protective devices are specialist pieces of equipment that might be found in laboratories or chemical production facilities, or in workshops where large quantities of known hazardous materials are present. 

Trade shortages 

As citizens purchase unprecedented quantities of protective respirators to lessen the risk of contracting COVID-19, there are serious concerns that tradespeople who depend on respirators for their everyday workplace safety will be left without supplies. At the time of writing, major retailers like Bunnings and Mitre 10 show severe stock shortages of common
N-95-rated masks.

One of the worst diseases currently affecting Australian workplaces is silicosis, which is an incurable lung disease caused by exposure to silica dust. Stonemasons, as well as workers dealing with engineered stone products for use in kitchen or bathroom benches, etc., are most at risk. Anyone involved in these kinds of commercial activities should wear an appropriately rated respirator at all times. As reported by the ABC2 in late 2018, there were 300 cases of silicosis detected in 2018 (up to December) in Queensland alone, with similarly alarming figures in all other states and territories. Described at the time by a spokesperson for the Thoracic Society of Australia and New Zealand as the worst occupational lung crisis since the height of asbestos-related illnesses in the 1960s and 1970s, silicosis may be aggravated by the presence of exotic chemicals in newly developed engineered products and adhesives, which means dust might include a range of contaminants apart from silica.  

Woodworkers exposed to sawdust also need protection against the inhalation of particles, as highlighted by a Cancer Australia report3 citing nasal cancer as the major kind of cancer linked to prolonged exposure. 

Painters, bricklayers, concreters, insulation installers and any other workers in dusty environments should always wear suitable protective equipment.

Bunnings and Mitre 10 are already showing severe stock shortages of common N-95-rated masks.

Even short-term exposure to foreign particles can lead to lung disease or death, according to the American Lung Organisation.4 

The lesson is clear: if common respirators are temporarily unavailable, then the wisest course of action for trade users is to obtain a higher-rated respirator than might normally be required, even if costs appear prohibitive. It is better to be safe than sorry, as the saying goes.

Footnotes

1. See www.envirosafetyproducts.com

2. See “7.30”, ABC, 10 October 2018. By Michael Atkin.

3.“Risk Factors for Lung Cancer: A Systematic Review.” Australian Government; Cancer Australia. 2014.

4. See www.lung.org.