Neil Webster, CSP, OHST, Contributor
Construction can be a pretty dirty business. Over 2 million workers in the U.S. have regular exposure to dusty conditions at work. Approximately 90% of those 2 million are employed in the construction industry.
A commercial construction project subjects personnel to a wide variety of conditions, including noise, vibration, weather, uneven working surfaces and numerous respiratory hazards. Injury and illness data
indicate a direct correlation between elongated work in the construction industry and future health-related issues for those that work in the trades.
Let’s break up a typical interior building renovation project into two basic phases—demolition and new installation—and examine the general activities and variety of respiratory hazards that can be present in each phase.
During the demolition phase, trade workers can expect to be exposed to an abundance of airborne particulates that can occur during the breaking, crushing or chipping of existing materials to make way for new materials. Common activities in a common project include:
Concrete removal: concrete mixes contain large amount of quartz (silica) and limestone
Drywall removal: gypsum exposure possible
Carpet removal: carpet fibers and general dust accumulated in the carpet
Ceiling tile removal: possible exposure to cellulose (The tops of ceiling tiles always contain dust, especially if the metal deck above has sprayed on fireproofing, which commonly contain slag wool and Portland cement.)
Steel removal using a torch: lead fumes and other metal fumes
Insulation removal: fiberglass and rockwool
The installation phase contains plenty of opportunities for exposure to airborne hazards. Typical activities in this phase include:
Cutting wood: sawdust generation
Installing drywall: gypsum dust
Sanding joint compound: quartz, limestone, perlite dust
Daily housekeeping (sweeping): general nuisance dust and whatever debris falls to the floor during installation activities
PVC Pipe installation (primer and solvent cement): methyl ethyl ketone, acetone, cyclohexanone
Tile mastic: limestone, quartz, volatile organic compounds (VOCs)
Metal pipe installation: soldering fumes
Duct sealant: VOCs
Latex (water-based) paint application using an airless sprayer: polyvinyl acetate, titanium dioxide.
How Much is Too Much?
As you can see, there are plenty of opportunities for personnel on the site to inhale a wide variety of contaminants throughout the entire project. How many industries have the potential for these constant respiratory exposures (and in different settings and constantly changing environments) to exist day after day, year after year?
OSHA lists an 8-hour, time-weighted average exposure limit of 15mg/m3 for total dust exposure to Particulates Not Otherwise Regulated (PNOR) and a respirable dust exposure limit of 5mg/m3. Many of the particulate exposures a trade worker would commonly be exposed to fall under this standard. Even so, samples for total dust and respirable dust are not commonly collected during construction work.
Of the data that is collected, it indicates that tradespersons in general have total dust exposure well below OSHA levels. We should keep in mind that the total dust and respirable dust exposure limits set by OSHA are decades old. Silica exposure, which causes silicosis, a serious health condition which causes premature death, has gained some traction in the last 20+ years—for good reason. However, daily exposure to dusty conditions, as found every day in the construction industry, is not healthy—especially considering the synergistic effect of particulate inhalation and cigarette smoking, which is still fairly prevalent in the construction industry.
How to Reduce Risks
So, what can be done? The use of wet methods during the demolition phase will absolutely reduce airborne particulate exposure for not just the demolition crew, but the entire work site. Using water or water mist to reduce airborne concentration of dusts is possible, but not always feasible. Issues include lack of availability, constant cleanup, freezing conditions in cold weather, causing slippery conditions, etc.
The next best option, utilizing negative air pressure, also significantly reduces airborne particulates. Containing a demolition project to be able to produce an adequate negative pressure environment is also possible—but again, not always feasible, because of logistical issues around creating the necessary airflows for contaminate reduction.
Using vacuums instead of brooms only have limited applicability. That leaves most projects in the position of combining an engineering control (such as water mist) with personal protective equipment (respiratory protection) to keep personnel safe.
The construction industry has struggled for many years with proper respiratory protection for the workforce. Complying with regulations is important, but gaining employee acceptance is everything. After being properly trained and fit-tested, if a tradesperson finds their respiratory protection to be uncomfortable; doesn’t have the right look; or is extremely inconvenient, the likelihood that they will continue to wear that respirator falls dramatically.
The respirator of choice for the construction industry has been the N95 due to its light weight and availability. More important is the N95’s high level of convenience, due to its disposable nature. Case studies at workplaces that require moderate respirator use show the annual total cost of ownership (per wearer) for a disposable N95 mask is extremely high compared to the cost of re-usable, half-face air-purifying respirators fitted with HEPA cartridges. However, the culture of the construction industry leans towards the disposability of an N95, and that remains the standard.
The lack of availability of the N95 due to the COVID-19 pandemic has caused many tradespersons to wear inadequate or no respiratory protection. While half-face, air-purifying respirators with HEPA cartridges have been available during the pandemic, the overall culture of the construction industry does not support an instant change to re-usable respiratory protection.
Clouds of dust have been widely accepted as an effect of construction work. It’s way past time to change the narrative. IHW
Neil Webster, CSP, OHST, is the EHS Manager for DPS Group, a full-service engineering and construction management firm that specializes in the Life Sciences industry.