This Article explores air sampling pumps, the background of standards and performance and why they are important.

Good news, the ILO Declaration on Fundamental Principles and Rights at Work [1], originally adopted in 1998 has been amended this year to include the basic right to a safe and healthy working environment.  The declaration is an expression of commitment by governments, employers' and workers' organizations to uphold basic human values - values that are vital to our social and economic lives.

 

Bad news, the Health & Safety community has been ‘shouting safety and whispering health’ for many, many years and when it comes to the air sampling pump, the ubiquitous tool for determining airborne hazards, well, it's near silence; they just seem to get taken for granted.  So what? Who cares? Airborne hazards can kill!  It’s the chronic nature of the long-term exposure to toxic dusts and vapours in workplace atmospheres that can take many years to develop into respiratory diseases and cancers which means that health is ‘less obvious’ than more visible, acute safety issues. And yet, the ILO’s own joint figures with the WHO [2] show that deaths from non-communicable diseases outweigh those from fatal workplace accidents by a factor of 5:1. In human terms, that’s a total of almost 2 million people who die from work-related causes each year (about a quarter from respiratory disease and cancers from airborne sources).  That’s simply unacceptable, when you think that deathrate is of the same order of magnitude as those who died during the COVID-19 pandemic, estimated at 2-3 million globally.

 

So, turning to the pump, the French National health & safety research institute (INRS) a similar body to the HSL in the UK and NIOSH in the USA, proposed a study in 2017 [3] to help customers choose a suitable sampling device. Unfortunately, the study has been delayed twice, most recently due to the global pandemic; the irony is not lost that another pandemic-like number of people have died prematurely from respiratory disease and cancers in the intervening five years.

 

Of the sampling pump, the INRS abstract said that “(it) is an essential component in the overall process of assessing occupational exposures to chemical and biological agents. The quality and representativeness of the result depend in part on its performance. Many parameters can influence the performance of a pump: its components, the type of trapping device associated with it and the environmental conditions. In addition, depending on the type of pollutants sampled, the conditions of use of the pumps can be very different”.

 

The INRS go on to say that “No pump is completely versatile for all types of sampling. Faced with the variety of commercial offers and the scarcity of technical information on the subject, the user can quickly find himself helpless to choose the equipment best suited to his needs. We therefore propose in this study to evaluate the performance of pumps available on the French market by subjecting them to the tests of the NF EN ISO 13137 standard which set the requirements to be met for this equipment”. 

 

The referenced ISO13137 [4] standard itself, first published in 2013, is now in the process of being reviewed and according to the standards Secretariat, it will be published in late 2022.  The current version replaced an earlier standard EN 1232 [5] itself also the subject of an INRS study [6].  However, most of the pumps tested then (2008) are now obsolete, so a reprise of the latest generation of pumps against a new revision of the standard is much anticipated otherwise it’s a case of caveat emptor, as implied in the INRS abstract.  Why? Because the 2008 study and others [7], have found discrepancies in the pump performance against the standard particularly in the area of allowed pulsation. Its’ very easy for manufacturers to simply state that their pumps are “designed to meet” the standard but we know that design compromises can occur, and all pumps are therefore clearly not created equal.

 

Casella first started producing personal sampling pumps in the 1960s, its first prototype being housed in a bicycle lamp.  Things have come a long way in the intervening six decades, but pumps today essentially still do the same job as they did then i.e. draw a known volume of air through appropriate sampling media. Gravimetric data and analysis from sampled filters and sorbent tubes remains the preferred method of calculating exposure for hazardous substances. Until real time personal dust measurement can gain equivalency with these methods in a usable format, it will remain so.  Some employees already baulk at personal sampling as a BOHS Ignite session [8]I’m not wearing that” once highlighted.  This attitude could well lead to employees taking the pump off, so gaining worker’s participation is paramount.

 

With this is mind, technology has moved on with a focus on connectivity and motion sensing to check pump performance and wearer compliance respectively but in terms of size and weight it may seem like sampling pump design has remained static.  However, despite the perception that “it’s just a pump”, innovation in pump design has moved on apace because the publication of the ISO standard demanded certain performance levels and that has driven manufacturers to improve their designs. The designer’s mission is to improve battery life and back pressure capability versus producing more lightweight, quieter pumps whilst simultaneously ensuring flow control and minimised pulsation, including an easy to use, instinctive user-interface, motion sensors, connectivity and data download. It’s quite a balancing act and overlaying all that is the need for intrinsic safety approval so that they can be used in the most hazardous environments found in petrochemical and pharmaceutical applications.  Add in the customers’ desire for a cost‐effective solution and I think you’d agree that it is quite a challenge!

 

Essentially a pump must run with a constant flow rate over the length of the sampling period; perhaps an 8-hour shift with the loading of the media creating a back pressure which makes the pump work harder, which in turn drains the battery faster.  If the pump cannot cope and fails then the sampling opportunity may be lost, which may mean having to repeat a day’s work or if this is during plant turnaround where the opportunity may not arise again for a year, it is definitely a serious issue.

 

All pumps are not created equal? QED! We look forward to the content of the revised standard, the eventual results of the INRS study and a renewed commitment to the ILO Declaration to ensure healthier outcomes for the global workforce.

 

References

1.       ILO Declaration on Fundamental Principles and Rights at Work (DECLARATION)

2.       WHO/ILO joint estimates of the work-related burden of disease and injury, 2000-2016: global monitoring report

3.       Résultats de la recherche simple - INRS

4.       https://www.iso.org/standard/79682.html?browse=tc

5.       EN 1232: 1997 Workplace atmospheres. Pumps for personal sampling of chemical agents. Requirements and test methods

6.       Performance des pompes de prelevement individual. LANGLOIS E., MORELE Y., LHUILLIER F. INRS ref ND 2297, 12/2008

7.       Evaluation of pump pulsation in respirable size-selective sampling: part 1 Pulsation measurements: Eun Gyung Lee, Larry Lee et al.  Ann. Occup. Hyg., 2014 Vol.58, No 1 60-73

8.       ‘I’m not wearing that’ a presentation by Jason Trebble, Airbus at the 2014 BOHS conference