Equipment
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Cyclone
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A cyclone is a type of sampling device used to collect respirable airborne particles. It uses a centrifuge to separate particles of varying sizes for sampling.
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Filter Cassette
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A filter cassette is a device used to collect airborne particles such as dust and aerosols. It consists of a plastic or metal housing that contains a filter medium.
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Filter Medium
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The medium used to catch particulates, typically made of materials such as PVC, paper and cellulose.
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Sampling Media/Collection Media
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The material used to collect or transport airborne contaminants.
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Sampling Train
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A series of components that are connected to collect and measure airborne contaminants. This generally includes a pump for drawing air, tubing and filters or sorbents.
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Sorbent Tube
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A tube containing sorbent through which air is drawn to trap airborne chemicals. This sample is then taken to a laboratory to be analysed.
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Calibrator
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A device used to gauge how much air has been pulled or pushed through the collection media. Calibrators such as the Chek-Mate Calibrator ensure that flow rate readings are accurate, accounting for changes in humidity and atmospheric pressure.
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Sampling Methods and Processes
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Active Sampling
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A method of air sampling that involves drawing air into a sampling device using a pump through the appropriate sampling media.
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Passive Sampling
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A method of air sampling that relies on the natural movement of air to bring contaminants into contact with a collection medium. Passive sampling equipment can only be used for measuring gases and vapours.
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Constant Flow
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Constant flow refers to the maintenance of a constant rate of air flow during the collection of air samples. This is typically achieved using a sampling pump such as the AirChek Essential Air Sampling Pump that is designed to deliver a constant flow rate of air over a specified sampling period. A calibrator is also used to ensure that the flow is measured accurately.
Maintaining a constant flow rate is important in air sampling because it ensures that the concentration of airborne contaminants is accurately measured.
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Gravimetric Sampling
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A method of air sampling that involves collecting particles on a filter and measuring the weight of the filter before and after sampling to determine the mass of particles collected.
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High Flow Sampling
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The collection of airborne contaminants (typically particulates) at flow rates greater than 1000 ml/min. A higher flow rate can increase sensitivity for sampling lower concentrations.
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Low Flow Sampling
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The sampling of airborne contaminants (typically gases and vapours) at flow rates less than 500 ml/min. |
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Flow Rate
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The rate at which air is drawn through sampling equipment. This is often measured in millilitres per minute (ml/min). |
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Personal Sampling
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The measurement of airborne contaminants in the breathing zone of an individual. |
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Adsorption
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Adsorption refers to the process by which airborne chemicals or gases are collected onto a medium where they may react or dissolve. Adsorption is used to collect chemicals or gases that are not captured effectively by other air sampling methods, such as particle filters.
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Breathing Zone
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The area immediately surrounding a person's nose and mouth within approximately 20cm. |
Airborne Contaminants
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Airborne Contaminant
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Any substance that is present in the air and may pose a health hazard including gases, vapours and particulate matter.
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Aerosol
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A suspension of microscopic liquid or solid particles in the air.
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Bioaerosol
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Bioaerosols are airborne particles of biological origin such as bacteria, viruses, fungi, pollen, and other microorganisms. These particles can be emitted from a variety of sources can have a significant impact on human health, causing allergic reactions, respiratory diseases, and infections.
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Particulate Matter
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Particulate matter is a term used to describe a mixture of solid and liquid particles that are suspended in the air such as dust, soot and smoke. Measured in micrometres, particulate matter can cause irritation and be breathed in by individuals working near their source.
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Inhalable Particles
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Light Particles that are small enough to be inhaled into the nose or mouth (100 μm 50% cutpoint).
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Respirable Particles
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Respirable particles are a sub-set of inhalable particles, and are fine enough to be able to penetrate into the gas exchange region of the lungs (4 μm 50% cut-point). These particles are especially dangerous as they cannot normally be seen, but can cause serious lung and heart diseases among other health effects.
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Respirable Crystalline Silica (RCS)
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Fine silica particles that cannot normally be seen but can reach deep into the lungs and cause a variety of serious respiratory and cardiovascular diseases including lung cancer and silicosis. RCS is common in industries such as construction, and it is vital that.
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Volatile Organic Compound (VOC)
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VOCs are a class of organic chemicals that can evaporate into the air at room temperature and often pose significant health risks. They are used as industrial solvents and are emitted by many household products. Photoionisation detectors (PIDs) are commonly used to detect VOCs.
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Total Suspended Particulate (TSP)
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The sum of all particles suspended in the air, including both fine and coarse particles.
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Exposure Standards in Australia
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Workplace Exposure Standard (WES)
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The maximum concentration of a substance that a worker can be exposed to over a specific time period without adverse health effects. Workplace exposure standards are enforced in Australia by Safe Work Australia and state specific authorities.
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Time-Weighted Average (TWA)
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A measure of the average concentration of a contaminant in the air over an 8-hour time period. The TWA exposure standards generally require exposure to be kept below this value, but allow exposure above this value for short periods if compensated by equivalent exposure below the standard.
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Short Term Exposure Limit (STEL)
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A 15-minute time weighted average exposure limit that absolutely cannot be exceeded, even when exposure is kept below the TWA.
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Peak Limitation
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Certain substances are assigned a peak limitation which cannot be exceeded at any time. These substances can have adverse effects in high concentrations, even over brief exposure periods. Given the analytical constraints of measuring certain substances, the timeframe for measuring exposure to adhere to the peak limitation should be the shortest period analytically possible without exceeding 15-minutes.
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