Industrial hygiene measurements of airborne platinum
IPA sampling and analysis method
IPA Harmonised Methodology for the Sampling of Platinum in Workplace Atmospheres
Knowledge about workers exposures to platinum is crucial to understanding the associated risks as well as the effectiveness of implemented operational risk reduction measures. Various sampling and analysis methods of differing performance have historically been used to measure occupational platinum exposures.
IPA, in collaboration with the University of Wisconsin, USA, developed a method for use across the industry following a review of the available equipment and testing and improving the limits of detection.
The method is described in the IPA guidance document IPA Harmonised Methodology for the Sampling of Platinum in Workplace Atmospheres.
A summary of the University of Wisconsin report, and access to the full study report, is available here [insert link to Wisconsin Report]
Analytical proficiency testing programmes
Monitoring the performance of facilities using the IPA harmonized method through the regular participation in laboratory proficiency testing round robin exercises provides further assurance in the results obtained through industrial hygiene monitoring.
Sampling and Analytical Method Performance for Platinum Monitoring in an Occupational Hygiene Context
The objective of this project was to develop a comprehensive protocol detailing sampling and analytical methods that together will achieve the lowest practical limits-of-detection for occupational/industrial hygiene monitoring of soluble platinum.
After a review of the literature and discussions with industry experts, the following samplers were considered for further study as meeting most of a critical set of selection criteria:
1) An IOM operated at a flow rate of 2 L/min (the reference sampler). Collects the Inhalable Fraction of PM
2) A 37mm closed-face cassette (CFC) operated at 4-5 L/min. Collects a pseudo-Inhalable Fraction of PM
3) An SKC Parallel Particle Impactor (PPI) operated at 8 L/min. Collects the Respirable Fraction of PM
4) An SKC PPI operated at 2 L/min. Collects the Respirable Fraction of PM.
From the outcomes of laboratory blank and spike recovery experiments using chloroplatinates, more extensive field studies were conducted at a PGM facility in the USA with both Teflon and mixed cellulose ester (MCE) media and lessor effort with PVC media, in combination with the selected samplers.
The 'soluble platinum' extraction fluid, extraction time and agitation, extractant volume and a number of operational parameters, such as cleaning and media pretreatment, were characterised.
The studies identified the IOM (2 L/min - inhalable) and PPI (8 L/min - respirable) samplers configured with MCE filters as the optimum sampler/media configuration.
Field studies were then carried out at six facilities on three continents by IPA scientists and healthcare professionals, in order to test the efficacy of the laboratory and single facility trials and to broaden the industry experience with the new methodologies. Where comparable, these extended field trials confirmed the original studies.
Following the above program, an IPA workplace sampling procedure was recommended, which has since been incorporated into the IPA guidance 'Safe use of platinum group metals in the workplace' and is being widely adopted by the platinum industry.
This research programme has also been published in the peer-reviewed scientific literature as:
Shafer........ (2018) An Improved Method for Sampling and Analytical Measurement of Aerosol Platinum in Workplace Environments. ............................................