Reusable Respirators: Sustainable Protection from Silica Dust

A look at the good, the better and best respiratory protection.

• By Claudio Dente
• May 01, 2022

It’s common knowledge that there are many workplace hazards in industries like construction, mining and oil and gas engineering, but did you know that one of the most common and deadly risks is the exposure to silica dust? 

What is Silica Dust? 

Crystalline silica is a mineral that is found in natural materials like clay, sand, gravel, rock and stone. Quartz is the most common form of crystalline silica and in fact it is the second most common surface material accounting for almost 12 percent by volume of the earth’s crust. Quartz is present in many materials in the construction and landscaping industry such as brick and mortar, concrete, slate, dimensional stone (granite, sandstone) stone aggregate, tile and sand used for blasting. So, the most common materials used in building and landscaping all contain silica putting those who work with these materials at risk. Silica dust is released from these materials during high-energy operations like sawing, cutting, drilling, chipping, sanding and grinding. These fine particles of crystalline silica release into the air and become a hazardous respirable dust. 

Exposure to Silica Dust 

Silica dust exposure can occur during common construction tasks such as: 

• Masonry saws 
• Grinders 
• Drills 
• Jackhammers and handheld power tools, 
• Operating vehicle-mounted chipping tools 
• Operating crushing machines 
• Using heavy equipment for demolition or certain tasks 

Industries where employees are commonly exposed to silica dust include: 

• Mining where large amounts of silica dust are generated during cutting and extracting of stone and become trapped in the ventilating air 
• Cement production and handling (emptying or disposing of bags) and concrete cutting 
• Oil and Gas Engineering 
• Construction 
• Masonry 
• Asphalt manufacturing
• Demolition
• Foundry
• Abrasive Blasting
• Quarries 

The Risks

Exposure to fine particle of silica has been shown to cause silicosis, a serious and sometimes fatal lung disease, lung cancer, other respiratory diseases and kidney disease. Review studies in 2020 even showed damage to genetic material in crystalline silica works with adverse health effects because of DNA instability. In 2021, the dangers of silica dust are clear, and proper respiratory protection for workers is a non-negotiable thanks to OSHA. 

In 2016, OSHA issued two new standards to protect workers from exposure to respirable crystalline silica—one for construction and the other for general industry and maritime. According to OSHA, the construction industry has approximately 2,000,000 workers exposed to respirable crystalline silica in over 600,000 workplaces in the United States. 

In the OSHA guidance document, OSHA uses a benchmark 8-hour time weighted average exposure of 0.05mg/m3 of respirable silica dust as a point of reference in describing control measures utilized by the construction trades. (Short term exposure can be higher.) 

If your exposure is over 0.05 mg/m3 for an 8-hour TWA, you MUST take appropriate measure to protect the worker and surroundings.

OSHA notes that some organizations like NIOSH and ACHIG recommend even lower levels (0.025 as an 8-hour time weighted average) 

According to OSHA, there are two ways to determine silica exposure levels:

1. Air monitoring or 
2. Through identifying certain activities on the Table 1 of the Standard and complying with the dust control methods lists. 

Luckily, OSHA has already done some of the legwork for employers and identified procedures you need to put into place to ensure any silica dust levels remain with the permissible exposure limit (PEL). 

You can view Table 1 on their website for the standard. 

How Can You Protect Against Silica Dust? 

Implementing a respiratory program according to OSHA’s PEL is a non-negotiable to properly protect employees from Silica dust exposure. 

Shifting to reusable elastomeric respirators in 2022 can not only provide optimal protection against silica dust but is also one of the smartest things you can do for the environment and for your bottom line. Disposable respirators generate an enormous amount of waste which ends up in landfills or worse. Elastomeric respirators are a sustainable solution and are designed to be cleaned, decontaminated and reused. Because of this feature, one elastomeric can do the work of hundreds, if not thousands, of disposable N95 masks. 

Elastomeric half mask respirators (EHMR) provide an enhanced seal to the wearers face with many models providing the ability to adjust their suspensions. This is in stark contrast to disposable respirators which oftentimes only have two elastic bands that go around the head. These elastic bands do not allow for adjustment to mitigate excessive pressure on your face/skin. If you are a smaller or bigger person, you may not be able to achieve a proper fit due to the sizing limitations and lack of suspension adjustment. 

An EHMR program can have big cost savings particularly over the long-term. A recent study found that a network reduced the number of N95s needed by 95 percent by implementing an elastomeric mask program, costing the network 10 TIMES LESS per month than purchasing disposable N95’s. 

Good Respiratory Protection Solutions 

Disposable respirators. From 0.05 mg/m³ to .5 mg/m³ TWA 8 hours requires a NIOSH approved half-facepiece or disposable respirator equipped with an N, R, or P95 filter or higher with an Assigned Protection Factor (APF) 10. 

Pros 

• Thought to be economical 
• Lightweight 
• Universal fitting, some models available in multiple sizes 
• Exhalation valve model exhausts hot, moist air reducing heat buildup and improving user comfort 
• Crush resistant shell design increases product life and improves comfort 
• Elastic straps sonically welded to the mask and no staples 

Cons 

• Due to the possibility of working in high heat (ambient temperatures) and moisture due to wet tool usage, daily consumption may be high 
• Difficult to fit check when entering hazardous application 
• Will cause fogging on safety or prescription eyewear 
• Will cause nose bridge irritation 
• Will not fit well with ponytails or hair up in a bun 
• More expensive in the long run as you need to constantly replace 
• BIG Environmental Impact–create more waste 

Better Respiratory Protection Solutions 

Reusable N95 Half Mask Respirators. From 0.05 mg/m³ to .5 mg/m³ TWA 8 hours requires a NIOSH approved half-facepiece or disposable respirator equipped with an N, R, or P95 filter or higher with an Assigned Protection Factor (APF) 10. 

Pros 

• N95 filters protect against non-oil-based particulate aerosols and is the recommended choice of OSHA. 
• Replaces disposable respirators 
• Variety of mask materials; Silicone is most comfortable, Thermoplastic (TPR) or Elastomeric rubber not as soft but less expensive 
• No hotter than wearing a disposable style respirator 
• Provides an airtight seal 
• Multiple sizes allow for better fit and protection 
• We offer protective assembly to attach filter to half and full-face mask, protects from dirt, misuse and extends filter life 
• Easy to fit check before entering hazard work area 
• Replacement parts 
• More sustainable, less waste 
• Economical due to reduced filter consumption 

Cons 

• Requires cleaning and maintenance 

Best Respiratory Protection Solution 

Reusable Half Mask Diskit P100 Filter and Reusable Half Mask Respirators P100 Cartridge. From 0.05 mg/m³ to 0.5 mg/m³ TWA 8 hours requires a NIOSH approved half-facepiece or disposable respirator equipped with an N, R, or P-95 filter or higher. 

Pros 

• P100 cartridge eliminates 99.97 percent of dust particle vs 95 percent for 95 rated filter 
• Offers greater protection versus N, R, and P-95 rated filters 
• Replaces disposable respirators 
• No hotter than wearing a disposable style respirator 
• Provides an airtight seal 
• Multiple sizes allow for better fit and protection 
• Replace when breathing resistance occurs 
• Due to greater filter material area reduces loading resulting in reduced breathing resistance, extending filter life and reducing consumption costs 
• Cartridge case protects filter and extends filter life 
• Easy to fit check before entering hazard work area 
• Optional Prefilter protects P100 cartridge, extends life reduces breathing resistance and consumption costs 
• More sustainable, less waste 
• Cost effective in the long run when compared to disposables 

Cons 

• Requires cleaning and maintenance 

Ultimate Protection—If You Require Protection above APF25 

Reusable Full Face Mask Respirators. From .5 mg/m³ to 2.5 mg/m³ TWA for 8 hours, requires a NIOSH approved full-facepiece respirator equipped with an N-, R-, or P-95 filter or higher with an Assigned Protection Factor (APF) of 25. (FULL FACE RESPIRATORS PROVIDE AN APF OF 50.) 

Pros 

• New special composite silicone offers superior comfort and value 
• Certified by NIOSH as a universal size, reduces inventory of multiple sizes. 

• Optional filters: 
  • The N95 filters has protective assembly to attach filter to full-face mask, protects from dirt, misuse and extends filter life 
  • P100 cartridge eliminates 99.97 percent of dust particle vs 95 percent for 95 rated filter 
  • Diskit P100 Pancake style filter provides P100 protection and is a more economical solution then standard P100 cartridge. 
  • P100 Cartridge with optional prefilter extends life reduces breathing resistance and consumption costs 

• Easy to fit check before entering hazard work area 
• Replacement parts 
• Polycarbonate fog resistant lens protects workers eye/face area 
• Protective lens cover prevents scratching
• Economical due to reduced filter consumption 
• Less expensive than powered air purifying respirators 
• Option prescription lens frame 
• Less Environmental impact, less waste 

Cons 

• Requires cleaning and maintenance 

This article originally appeared in the May 2022 issue of Occupational Health & Safety.