Air sampling is an essential step in workplace safety, but it’s only part of the process. While using the right equipment and obtaining accurate data are critical, the real value lies in what happens after the assessment. It’s not enough to simply collect air samples and report on the levels of contaminants—we go beyond that to provide practical, tailored solutions that directly improve workplace safety.
Once sampling is complete, we collaborate closely with site management to offer targeted advice on implementing the necessary controls. Whether it’s reviewing the suitability of mask filters, suggesting alternatives for respiratory protection for workers with facial hair, optimising local exhaust ventilation (LEV) systems, or developing a focused occupational health screening plan, our goal is to ensure that the data we collect is actionable and leads to meaningful improvements.
In the conclusion of this blog, we dive deeper into these real-world applications, explaining in detail how our advice helps you avoid blanket approaches and instead implement specific, effective changes that make your workplace safer and more compliant with regulations. By focusing on why and how to make these improvements, we ensure that your air sampling results translate into proactive safety management and sustainable practices.
How to Perform Air Sampling on Site
1. Understanding the Substance and Its Hazards
Before selecting any equipment, it’s crucial to understand what you are sampling for and why it’s a hazard. For example, acetone used in industrial settings can pose health risks if inhaled over long periods, especially in poorly ventilated spaces. The why is simple: acetone is a volatile organic compound (VOC) that can cause dizziness, respiratory issues, and even damage to the central nervous system with long-term exposure. Knowing this, air sampling helps you confirm whether the exposure levels are within safe limits.
2. Choosing the Right Equipment
Once the substance and potential hazard are understood, choosing the correct sampling media becomes essential. For instance, when sampling for volatile organic compounds (VOCs) like acetone, you would typically use an active sampling method involving a pump and a sorbent tube. Here’s a step-by-step guide:
- Active Sampling: A pump is used to draw air through a sorbent tube or filter. In this example, if you’re sampling for acetone, you would use a Chromosorb 106 Tube (part number 226-358). The pump is calibrated to pull air through the tube at a set flow rate—usually measured in Liters per minute (L/min)—to capture acetone from the air.
- Passive Sampling: If the sampling period is longer, or if you’re working in a low-exposure area, a passive sampler (part number 575-002) may be appropriate. This device absorbs contaminants naturally through diffusion, with no pump required. It’s simpler and less intrusive but may take longer to collect a meaningful sample.
- Calibration and Setup: Before heading to the site, make sure to calibrate your pump using a flow calibrator. Calibration ensures accuracy, as even minor deviations can skew your sample results. On-site, place the sampling device within the worker’s breathing zone (usually within 10 inches of the nose or mouth) to capture representative air samples.
3. The Sampling Process
- Personal Sampling: When assessing worker exposure, attach the pump and sorbent tube to the worker’s clothing within the breathing zone. This method is useful when workers are directly handling hazardous substances, such as acetone in a spray-painting job. Monitoring during an 8-hour shift ensures the data reflects a real working day’s exposure.
- Area Sampling: If you need to monitor a specific area—such as a painting booth or a confined space where VOCs accumulate—place the pump in that area and leave it running for a predetermined period. This provides a good indication of the airborne concentrations in static locations.
- Why It’s Important: Without these accurate measurements, it’s impossible to know whether the working environment is safe or hazardous. For example, even if workers are using proper PPE like respirators, if the air in a confined space is saturated with harmful vapours, it could compromise the effectiveness of PPE, leading to overexposure.
Why Sampling Equipment Alone Isn't Enough
The equipment is only part of the solution. Knowing why you are sampling a specific substance and how it relates to workplace processes is crucial. Here are examples to illustrate the importance of understanding the broader context:
- Substance-Specific Hazards: Let’s take formaldehyde as an example. It’s commonly used in manufacturing and can be highly toxic if inhaled over long periods. The why is that it’s a carcinogen. By understanding this, you can make sure that your sampling approach focuses on areas where formaldehyde exposure is most likely to occur, like near adhesive application machines or resin-casting operations.
- Activity-Based Hazards: Consider a woodworking shop generating respirable dust. The particles released when cutting or sanding wood are tiny but can be harmful if inhaled. In this case, you need to consider when the hazard is most prominent (e.g., during active cutting). The sampling process might involve monitoring dust levels before, during, and after cutting activities to determine exposure trends.
- Processes and Controls: Often, workplaces use safety measures such as local exhaust ventilation (LEV) to reduce exposure. By sampling before and after such controls are implemented, you can assess their effectiveness. For instance, you might sample for solvent vapours during an industrial cleaning process to ensure that LEV is adequately reducing exposure. If not, the data will help justify improvements or increased monitoring.
Why Understanding the "Why" Makes the Difference
Knowing why you’re sampling not only determines how to set up equipment but also informs your entire risk assessment strategy. It’s essential to recognise that not all hazards are immediately obvious based on their perceived danger. As occupational hygienists, we develop a critical skill—the ability to assess both the obvious hazards and the hidden ones.
For instance, a very hazardous process, such as handling hydrochloric acid in a manufacturing plant, may be well-controlled with robust safety systems like local exhaust ventilation (LEV), airtight enclosures, and proper PPE. In these cases, the obvious hazard is present, but stringent controls mean it poses minimal risk under normal operation. While we may still monitor for compliance and efficacy, this scenario might not require intensive sampling.
On the other hand, a less hazardous substance—like wood dust from sanding operations—might be poorly controlled in the same facility. Although wood dust doesn’t carry the immediate danger of acid exposure, if workers are exposed daily without adequate ventilation or respiratory protection, the long-term health effects could be more significant. This is where our expertise is crucial. Spotting the less obvious, but more pervasive, hazards is key to ensuring a safe environment. In this case, it’s imperative to sample air quality in these work areas to determine whether exposure levels exceed safe limits over time.
Example: Identifying the Bigger Issue
In one case, a facility’s spray booth had all the proper controls in place for managing solvent vapours, reducing exposure to well below the regulatory limits. However, a storage area nearby, where workers spent time mixing these same solvents, had minimal ventilation. While the spray booth posed a higher initial hazard, the under-controlled mixing area turned out to be a greater issue due to cumulative exposure over time. By conducting air sampling in this “lower risk” area, we uncovered elevated solvent vapor levels that were not initially anticipated, prompting immediate action to improve controls.
This is why understanding the why behind air sampling is so critical. It allows us to focus not only on the high-hazard areas but also on the spaces where hazards may be overlooked or underestimated. Our role is to identify where the real risks lie, even when they aren’t immediately obvious, and provide data that informs better control measures.
Conclusion
Air sampling equipment and MSDS (Material Safety Data Sheets) are undeniably essential to occupational hygiene. The MSDS sheets provide the necessary chemical data, while the sampling equipment—whether it’s pumps, sorbent tubes, or passive samplers—collects the data that informs decision-making. However, while these tools are fundamental, the real value comes in how we interpret the data and help sites implement practical solutions that protect workers.
Beyond Sampling: Tailored Advice and Technical Solutions
- Mask Filters and Respiratory Protection Suitability When conducting air sampling, one of the crucial outcomes is assessing whether current personal protective equipment (PPE), such as face masks, is appropriate for the levels of airborne contaminants detected. For example, after sampling for volatile organic compounds (VOCs), we don’t just stop at stating the exposure levels. We evaluate the filters on the masks being used. Are they suitable for filtering out the detected contaminants? If VOC levels are high and the filters aren’t rated for these specific substances, we recommend alternative filters that will adequately protect workers.
- Technical Detail: Not all filters are designed for the same airborne hazards. For VOCs, for instance, you need organic vapor cartridges (e.g., A2 or ABEK filters) rather than particulate filters. This is a nuanced area, and our role is to ensure the right filter is used for the specific contaminants present.
- Alternative Solutions for Respiratory Protection: Addressing Face Fit Testing A common issue in workplaces is the need for workers to be clean-shaven to pass face fit testing for tight-fitting respirators. Many workers prefer to keep facial hair for personal or cultural reasons, which can present a challenge. Instead of forcing a one-size-fits-all approach, we suggest alternative respirators like powered air-purifying respirators (PAPRs). These respirators don’t require a tight seal to the face, allowing workers to maintain facial hair without compromising safety.
- Technical Detail: PAPRs use a battery-operated blower to pull air through filters, providing clean air to the wearer via a hood or helmet. This solution not only removes the need for face fit testing but also offers superior protection in certain environments with high contaminant levels.
- Occupational Health Screening: A Targeted, Risk-Based Approach Often, workplaces take a blanket approach to occupational health screening, which can be both inefficient and costly. Rather than testing all employees uniformly, we analyse the tasks and exposure levels based on the air sampling results and advise management on targeted screening for those at risk. For example, employees exposed to solvents may require spirometry tests to monitor lung function, whereas those exposed to loud noises should undergo audiometry.
- Technical Detail: This targeted approach means screening is focused on those who need it most, and unnecessary testing is avoided. For instance, regular audiometric testing is required for workers exposed to noise levels above 85 dB, but workers below this threshold do not need to be screened as frequently.
- Fine-Tuning Local Exhaust Ventilation (LEV) Systems Another area where we provide value is in LEV system assessments. After conducting air sampling, we don’t just recommend blanket changes to the entire system. Instead, we identify specific components that require improvement. For example, during a recent evaluation, we found that airflows in certain extraction hoods were too low to capture contaminants effectively. Instead of suggesting an overhaul of the entire system, we recommended adjusting the position of the hood or increasing airflow at specific points.
- Technical Detail: This can involve recalibrating fan speeds, adjusting duct sizes, or improving hood positioning to target high-contaminant areas. Ensuring that air velocity at the face of the hood meets minimum standards (e.g., 0.5 m/s for general applications) ensures contaminants are efficiently captured.
Our Expertise: Making Air Sampling Data Actionable
While accurate air sampling and the use of the right equipment are crucial, the real value we provide lies in how we translate the data into actionable improvements. We don’t just hand over reports and numbers; we work closely with site management to implement practical solutions that reduce exposure risks and enhance worker safety.
Whether it’s advising on the best mask filters, offering alternatives for face fit testing, or optimising the performance of LEV systems, our tailored solutions ensure that safety measures are both effective and sustainable. By focusing on targeted interventions, we avoid unnecessary costs and improve safety outcomes in a way that blanket approaches often fail to achieve.