We’ve reached the end of our Under the Microscope series – and today’s topic may be one of the least taken seriously despite posing a threat severe enough to be deadly.
When you think of hospitals and other healthcare centers, “dusty” probably isn’t a word that you would use to describe the image. On the contrary – “sterile,” “clean,” and “bright” are generally more accurate descriptors of these spaces. Hospital staff are extensively trained to maintain sanitation and cleanliness in every area of the building, but when a construction or remediation project is factored into the mix, keeping things clean suddenly becomes a bigger task. That’s why construction infection control dictates its own training for contractors who work in healthcare centers.
Dust and dirt can be brought into hospitals in a number of ways – but your job as a professional is to always keep any dust that is kicked up while working on an abatement, remediation, or other construction project contained.
Dust may seem insignificant to many of us, but it exists as an invisible threat to anyone exposed to high quantities – and for those with conditions such as asthma, lung disease, or weakened immune systems, breathing in even relatively small concentrations of dust can lead to dangerous health complications. Dust itself is only visible above the size of 10 microns – but exists airborne in sizes much smaller.
To put it in perspective, most standard air handling units (AHUs) filter dust particles down to 0.5 microns in size through the HVAC systems, and HEPA (High-Efficiency Particulate Air) AHUs – those designed to capture even more of the particulate matter in the air for exceptional indoor air quality – filter dust as small as 0.3 microns in size. In both cases, the threat being captured is microscopic, making it easy to miss. If you have ever been shocked by how much dust is captured by the air filter in your home, you know it’s not a good idea to be breathing that in.
Construction workers have historically suffered from the effects of long-term exposure to excessive dust on the job. Silicosis is one of a number of lung diseases that can result from breathing in mineral dusts that the lungs can’t get rid of – Silicosis specifically being caused by inhaling crystalline silica dust. This disease is prevalent in construction workers and is considered a “progressive” disease – causing those affected to have increasing difficulty breathing throughout the course of their lives, and sometimes even leading to premature death.
With a long list of diseases and complications that can arise from a healthy person inhaling the wrong type of dust, the risks are even higher in hospitals where you never know what types of preexisting conditions may cause severe reactions to relatively small amounts of dust in the air.
The key to preventing dust borne illness when working on a remediation project in a hospital is to first understand how much – and how quickly – your actions can kick up dust. Contractors use laser particle counters to measure concentrations of dust in the air. These devices allow them to provide baseline conditions before starting a project and document the effectiveness of Infection Control Risk Assessment (ICRA) measures. This not only holds contractors accountable if they don’t practice proper safety procedure (such as failing to build an airtight containment system) but also protects those who have done their due diligence from blame if someone wrongly tried to claim that dust from their remediation project caused an illness.
We had the opportunity to see a demonstration during our day at the Construction Infection Control Training Institute that opened our eyes to how quickly dust can accumulate in the air during remediation jobs. Here’s how it went:
Using a laser particle counter, the course instructor measured the concentration of particulate matter in the air in two locations (inside and outside) to serve as a baseline for the demonstration. The counts below indicate the number of particles greater than or equal to 0.3 microns in size:
- Inside a classroom fitted with a standard commercial HVAC unit: 39, 012 particles per liter of air
- Outside, immediately outside an exterior door connected to the same classroom: 80, 813 particles per liter of air
Next, the instructor stepped into an adjacent room connected to the classroom by an open doorway and turned on a commercial sanding machine – letting it run for a brief 3 seconds and quickly shutting it off. His next particle measurement was:
- From just outside of the doorway to the sanding room: 723, 193 particles per liter of air
That isn’t a small jump! Plus, it was from only 3 seconds of sanding – nowhere near the length of a full job. Imagine how much dust can become airborne during any project that involves sanding, demolition, spray painting, or the use of other high-powered equipment. Even though much of the dust is not visible, it still has a major presence in many jobsites.
Preventing Dust Spread
Containment systems are often indicative of abatement jobs, but they also serve as protective barriers in other types of construction and remediation jobs, especially in sensitive environments like hospitals.
When creating a containment system to contain dust, it is important to remember that the maintenance of a barrier is more important than how many layers it has, or if it has an anteroom. Even if there are multiple layers of the system, any failure can ruin the integrity of the whole thing.
ICRA defines four elements of control that are critical to preventing the spread of harmful dust during remediation and abatement jobs:
- Minimization – Reduce the severity
- Isolation – Confine to a controllable space
- Elimination – Remove from the area
- Monitoring – Ensures effectiveness of the entire strategy
These four principles should define how you approach your job.
What does it look like to follow best practices for containing and safely removing dust?
- Monitor dust levels daily using a laser particle counter, using outdoor air as a baseline
- When possible, use tools that prevent dust from being kicked up, such as airless paint sprayers
- Maintain a physical state of cleanliness as much as possible – check your clothes for excess dust before leaving your contained area
- Always use the right poly-hanging tape for your containment systems
Tape plays a critical role in containment systems – keeping the poly sheeting up and adhered securely to the doorframe, window, or other opening. Typically, a painter’s tape is used to protect the application surface from damage by offering clean removal, while a robust duct tape is relied on to adhere the poly sheeting to the backing of the masking tape. If one or both of the tapes fails – whether it fails to produce an airtight bond or comes loose before the project is complete – the entire system fails. That means lost time, lost money, damage to your company’s reputation, and ultimately, the compromise of the health of people in the facility.
When choosing tapes for hospital construction or remediation projects, look for masking and duct tapes that are purpose-built for poly hanging and designed to prevent containment failure. These types of professional tapes perform better than general-purpose masking and duct tapes, making them toolbox essentials.
Not sure you want to stock two types of tapes just for containment building? Look for a double-sided abatement tape with a dual adhesion system (painter’s tape adhesive on one side, duct tape adhesive on the other) for a quicker – but just as effective – alternative to the two-tape method.
To learn more about the importance of containment systems in hospital abatement and remediation jobs, check out our previous Under the Microscope Series blogs!
Source: Construction Infection Control Training Institute