Air sampling is a crucial component of ensuring worker health and safety. While workers generally understand the importance of the practice, many are not familiar with the actual process behind the procedure. In short, air sampling is the process of detecting and analyzing varieties and quantities of contaminants which workers may be subject to breathing in while on the job. From outdoor workplaces to indoor environments, chemical vapors and harmful respirable dust particles are used and produced when working with industrial or chemical materials, which can be hazardous to anyone who may be exposed.
One of the simplest ways to detect, identify and quantify harmful gas vapors and dust particles is the tried and true method of using an air sampling pump. While this process may seem intimidating, the truth is that it is relatively simple. Let’s review the components:
Air Sampling Pump
An air sampling pump is a small personal pump that can be used to draw in air that can (and should) be calibrated before each and every exposure to ensure an accurate reading on the environment. The pump is generally worn on the hip with the air intake tube attached to a shirt collar. This allows the sample to be collected from the breathing zone near the worker’s mouth. Connected to the pump is the sampling train which captures the hazard.
Cassettes, Filters and Sampling Bags
Cassettes, filters and sampling bags can all be used to collect the air sample. But, how do you know which is right for your unique environment? It’s actually a relatively easy process to identify what you need on the end of your sampling train:
- Gas = Impinger. This sorbent tube will collect and trap gas onto the end of the sampling train.
- Particulate = Filter. This material looks much like a coffee filter and is housed in a plastic casing called a cassette. You will need to the proper type according to your specific particle sizes. Respirable is considered dust small enough to enter the lungs, up to 10 microns in size, while total inhalable dust is measured up to 100 microns in size.
Select the proper cyclone This plastic or metal device causes the air to swirl to ensure that only the size of the particle you need to measure reaches the filter media.
Once you have determined your sampling train and connected it to your sampling pump, you will need to calibrate the sampling pump to the correct air flow volume. NIOSH or OSHA will have different flow rates for what hazard you are trying to detect. It is important to use the correct flow rate in order to determine the concentration of contaminants in the air that a worker will be exposed to. You can determine your rate using this calculation:
Concentration (mg/m3) = Weight Gain (mg) x 1000/Flow rate (l/min) x time (min)
The contents of the impingers or cassettes should be sent to the laboratory for analysis to ensure accuracy and proper test methods.
This method of air sampling guarantees accuracy and should be used by any company that may have respirable dust in their working environment.
It should be noted that the lab process takes time. The turnaround, which can take a couple of weeks, will be able to provide accurate insights on the sample that was collected at the time of the test. For this reason, digital sampling pumps are also available to help deliver immediate readings. While these testers are able to provide instant results, they may not be entirely accurate. As opposed to taking an actual sample of the air, digital sampling pumps use scattering light technology or condensation particle counting, which can be fooled by the sizes, shapes, colours and densities of particles.
Levitt-Safety carries a full range of air sampling products. If you need help choosing the right air sampling instrument for your work environment, get in touch with us today.