DIY Oil Testing
Progress toward community oil pollution analysis
As one of the core initiatives of Public Lab's Homebrew Sensing Project, the Oil Testing Kit is an effort to address one of the original challenges Public Lab faced after its founding during the Deepwater Horizon oil disaster -- that of identifying oil pollutants after a spill.
Public Lab believes that the co-development of tools and methods by and with people who directly face pollution is key to developing accessible and appropriate solutions. In that light, we've strived in this project to build open collaborations, to engage partners involved in oil pollution response, and to prototype and pilot a process which addresses local needs and remains legible and open to participation, from problem identification through field testing. To varying degrees, we have succeeded at some of these aims and not succeeded at others, and here we intend to document the project so that others may build on what we've done.
About this document
We've compiled this collection of writing in order to present an overview of the Oil Testing Kit program, synthesizing three main topic areas:
- Working with community: including notes on community and online outreach strategies, workshops and resources
- Questions, Motivations, & Best Practices
- Tools and methods: hardware, software, instructions and challenges
- Data and action: community oil testing and advocacy
Through the Homebrew Sensing Project and in this report, we have attempted to address community needs and site-specific environmental issues with affordable, co-designed, open source tools, and to collect data which provide compelling information about key questions regarding pollution. Over two years, we've had opportunity to try different strategies, to succeed and fail, to regroup and redesign.
Public Lab was founded just after the Deepwater Horizon oil disaster, and many of the tools we are developing focus on oil pollution and its effects. As one of the earliest, but longest-term projects we chose to focus on, Do-It-Yourself spectrometry has also been one of our most popular, with thousands of people constructing and using their own from various kits and instructions since 2010.
While the open source approach to tool design resulted in wide adoption, it did not produce a lot of interest in the specific problem of identifying or distinguishing oil pollutants. With this in mind, we set out to launch a new project in 2013-4 to launch a more focused -- but still open and collaborative -- effort to distinguish oil pollutants. We chose to explore using ultraviolet fluorescence: the principle that different oils fluoresce different colors, measureable by a spectrometer, when illuminated with ultraviolet light. This involved a series of progressively more difficult challenges, which we will discuss in this document.
Who is this document for?
We’re writing this for multiple audiences, who have varied interests and experiences with oil and spectrometry. We’re hoping that everyone finds information useful to them within this document and that the case studies, event models, and analysis on our process will be helpful to anyone who seeks to:
- join and further Public Lab’s oil testing program
- understand the history and current state of the Oil Testing Kit
- conduct experiments using DIY spectroscopy
- develop their own community technology development project
- advocate for accessible oil testing
In this document we’ve tried to keep the technical language to a minimum, and have included a glossary for some potentially unfamiliar terms.
- pilot DIY differentiation of oil pollution samples (using UV fluorescence)
- refine and simplify DIY spectrometer construction
- develop and test DIY sample collection and analysis methods
- improve software for easy analysis of samples
- prototype open and collaborative patterns for technology/methods development
- create and refine community engagement models for such development
- develop a tool to assist people in narrating their experience with oil
Our more specific goals as we conclude this program include:
- assess DIY fluorescence spectrometry open hardware kit design
- evaluate DIY fluorescence spectrometry analysis methods
Questions, Motivations, & Best Practices
Public Lab’s Oil Testing Kit program has set out to develop a **low-cost, Do-It-Yourself kit for differentiating oil pollution, building on the DIY spectrometry kit Public Lab has designed and distributed since 2011.
There are many different questions which such a kit might attempt to answer, and it's important to address them individually. Asking questions is how we started Public Lab, and questions are at the heart of Public Lab's process of research and development. We've collected many common questions here -- many, but not all of which, we can now answer. Here, we have tried to order each group of questions with increasing difficulty or complexity.
[image of tarball]
Imagine you find (as many of us did) what looks like tar on the beach after an oil spill:
How do I tell if it's oil or something else, like a piece of a tire or asphalt, or mud?
The technique we’re using, called steady-state ultraviolet fluorescence spectroscopy, has been shown to be able to distinguish between different weights of oil -- such as crude oil versus motor oil or diesel -- in a laboratory under certain conditions (see Literature section). The kit we’re developing also attempts to differentiate categories of oil, without laboratory facilities and instrumentation. To do this, there are many unknowns remaining; including:
- the effects of weathering
- false positives (read on)
There are also other materials which fluoresce, such as various types of organic matter. Fluorescence alone cannot be used as evidence of petroleum: rotting vegetation or even olive oil or beer will fluoresce, but because the spectrum of each will be different, the theory is that a spectrometer will help you tell plant matter apart from a petroleum sample. However, as of January 2016 this has yet to be clearly demonstrated in our community, and we hope that the refinement of the testing kit itself will make such tests easier to perform.
It’s important to note that, while different kinds of oils have been distinguished by a given user using their specific instrument, not every user has been able to do so, and the results have not always been consistent among different spectrometers. Thus, we are still working to improve the reproducibility of our method, which is fundamental to being able to distinguish grades of oils, or oils from non-oil fluorescing materials (see “Testing Our Hypothesis” in Workshop 1).
How do I tell if it's oil from the spill in question?
Matching an individual source of oil, such as crude specifically from the Deepwater Horizon spill, is known as “spectral fingerprinting,” and according to the scientific literature, the technique we are using (“steady state ultraviolet fluorescence spectroscopy”) does not produce spectra that are unique and specific enough to distinguish samples from one source from another if they are very similar.
However, if there is only one source of crude oil in an area, and you wish to collect evidence that a sample is from that source, as opposed to being motor oil or diesel, or some other pollutant, then this is the test we are attempting to reproduce with a DIY kit. (See previous question.)