The Dos and Don’ts of Using Air-Sampling Pumps
Best practice advice to protect your workforce from exposure to hazardous substances
It is estimated that every 30 seconds, somewhere in the world, one worker dies as a result of exposure to toxic chemicals, pesticides, radiation and other hazardous substances1. The effects of exposure can develop quickly or take years to develop, leaving workers vulnerable to asthmatic and allergic reactions and longer-term illnesses, such as cancer and cardiovascular, respiratory and nervous system disorders. While the cost to human health can be devastating, the financial costs to businesses through reduced productivity, employee absences, recruitment and compensation claims can be substantial.
OSHA issues citations and penalties if businesses violate permissible exposure limits (PEL). PELs are legal limits designed to control employee exposure to hazardous substances in an 8-hour period to prevent health risks. However, employers are also advised to monitor recommendations from industrial hygiene experts and manufacturers, because it is estimated that 90% of OSHA’s PELs have not been updated since the 1960s2. Consequently, OSHA may issue citations under the general duty clause of the Occupational Safety and Health Act (OSH Act) if exposure limits exceed industry-wide standards and pose a threat to employee health.
Industrial hygiene methods are geared towards measuring personal exposure using personal air-sampling pumps, because the tried-and-tested method can quantify personal exposure and ensure compliance with regulatory limits. To support effective monitoring and compliance with safety standards, here are some of the dos and don’ts of using air-sampling pumps.
Safety Many pumps are intrinsically safe (IS) rated as standard, but it is worth checking that your pump’s IS rating is still appropriate for your facility to avoid any safety issues.
The Design Size, weight and accessibility are critical design elements. Pumps should allow freedom of movement, as well as be unobtrusive, robust and not prone to leakage. Selecting a smaller, lightweight, low-flow pump (0.05-1L) for sampling vapors and gases, over a medium-flow pump (1-5L) equipped with a low-flow adaptor, is more user-friendly for workers. When using a sorbent tube, managers need to check that the smaller (backup) section is nearer to the pump.
Calibration All pumps should be calibrated with representative sampling media before use. It is also necessary to calibrate the pump before use; be sure to check again at the end of the day to make sure to make sure flow has not deviated by more than 5%. Of course, make sure you are calibrating the whole sample train, not just the pumps, to ensure accurate measurement.
Standards It is vital to check that your pump meets the latest international standard for air-sampling pumps. Compliance to ISO 13137 ensures accurate flow performance amongst other performance criteria, ensuring accurate sampling and meaning you won’t have to repeat measurements.
Pulsation If you are using a cyclone, do not assume that your pump has sufficiently low pulsation. The ISO standard states that this should not exceed 10% of the flow rate. A large pulsation value means that the size cut performance of cyclones used can be affected, because their performance is flow-rate dependent. Consequently, pumps that generate significant pulsation will collect smaller samples, meaning less data to analyze. Updates in some of the latest electronic flowmeter mean pulsation can be measured.
Pump usage Don’t leave your pump unused and uncared-for. If you don’t use your pump regularly, charge or cycle the battery, so when you do need it, the battery will last. Pump care is critical, so after sampling, check for damage and get your pump serviced at the prescribed interval.
Save Time, Increase Confidence
The latest generation of Bluetooth®-enabled pumps and flow calibrators can automate the calibration process and save valuable time, increasing confidence in the calibration results, which can be saved and/or emailed for reporting. Pulsation, once tested in a laboratory, can now be checked in the field at the same time as a normal flow rate calibration, through an airflow calibrator equipped with Bluetooth. As advances in technology continue to develop, remote methods can avoid disturbing workers and improve the validity and reliability of sample data.
Skill and knowledge of air sampling can take years to build, so the information above can only be considered a foundational introduction. If certain aspects of air sampling are outside of an individual’s competencies, external consultancies, training and support can be sought to bridge knowledge gaps and ensure employees get the critical protection they need. However, these practical steps will help keep employees protected throughout the working day by ensuring air-sampling pumps identify hazardous amounts of fumes, dust and gases that can increase the risk of long-term damage to worker health.
[Tim Turney is Global Marketing Manager at Casella and graduated as an engineer from Queen Mary and Westfield in London. Since starting at Casella in 1998, Tim has been involved in the acoustics and air sampling industry, specializing in measurement and instrumentation technologies. www.casellasolutions.com]