Webinar 33 | Is “TPH” always TPH? - What has your lab actually measured?

About the webinar

Most of us are either asking our lab for a particular “TPH” test or receiving “TPH” results specified by someone else. What most people are not asking is whether the received ”TPH” results are fit for their intended purpose, whether that be for human health risk assessment, waste classification, passing WAC and/or finding out what the actual source of the hydrocarbons might be. The challenge is that the labs offer a variety of “TPH” tests, all with different methods and different names, such as EPH, TPH, TPH1, TPH-CWG, mineral oil etc. Unfortunately, these terms mean different things to different labs including different test methods. Critically, getting the wrong test, or not actually understanding what a particular “TPH” test actually entails, can give you concentrations that can cause your waste to be hazardous, fail inert WAC or exaggerate certain bands in your human health risk assessment. [Have you ever wondered why you failed inert WAC for mineral oil (900 mg/kg) whereas your TPH CWG results  (400 mg/kg) were fine? - or why your TPH-CWG results are much larger all of a sudden?]   

The most significant reason why you might get higher concentrations is because the lab hasn’t done a clean-up –  A clean-up  attempts to remove non-petroleum hydrocarbons, such as the humics and fatty acids, both naturally  organic compounds found in soils and not related to petroleum hydrocarbon contamination and gives you lower concentrations.  This lack of transparency and ambiguity has been further compounded by the introduction of GC-GC (or 2D Gas Chromatography) technology by many UK labs, which has only made the problem worse, especially for the TPH-CWG test.  

This talk will explain:

• The basics of 1D and the new 2D gas chromatography and the analysis of hydrocarbons
• What a clean-up step does and why it is important
• The impact that getting the wrong test can have on your analysis – for example, increased disposal costs
• How we have addressed the problem: the introduction of the HWOL Acronym System across all the UK labs. This system provides a description of the type of TPH test (eg EH_1D_Total) and whether the test includes a clean-up step (eg EH_CU_1D_Total) 
• Using more than one “TPH” test to get more information about the nature (source) of your hydrocarbons

About the speaker

Dr Ian Bishop is Founder & Managing Director  of One Touch Data.  Ian’s company produces and supports the industry standard hazardous waste classification software, HazWasteOnline™. His background includes geology, geophysics and environmental data management and 16 years working for Golder Associates. He started One Touch Data in 2008, just as the banking system crashed; the crisis leading to a change in direction and the development of HazWasteOnline™ which has become the go to software for waste classifiers in the UK and Ireland. Today, he spends a lot of time working with stakeholders to help improve standards and understanding across the industry.

[Image credit: Gas chromatography vial, syringe and column by Geoffrey Whiteway.  Available at https://www.stockvault.net/photo/195160/chemistry#]