Hi @hulalupa -- I would like to add my welcome to Connect along with @lisalucier and other members here. The best thing you can do is learn as much as you can about the testing and be a strong advocate for yourself. These links were in earlier posts but I thought I would repeat them here.

Links I've found that point out the problems with the current PEth testing:

Against the Rising Tide: Looking for Biostatisticians and Epidemiologists to help shape Drug-Testing Policy to be more Evidence-Based
— https://disruptedphysician.com/2014/12/01/against-the-rising-tide-looking-for-biostatisticians-and-epidemiologists-to-help-shape-drug-testing-policy-to-be-more-evidence-based/

ETG/ETS – A Physician Criticizes the Tests and Lack of FDA Oversight (law firm website)
— http://www.rockindlaw.com/etgets-a-physician-criticizes-the-tests-and-lack-of-fda-oversight/

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions
— https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4598755/

I also found a lot of research information on Google Scholar (https://scholar.google.com/) using the search phrase "peth alcohol test false positive". Here are the search results links:
— https://scholar.google.com/scholar?as_ylo=2018&q=peth+alcohol+test+false+positive&hl=en&as_sdt=1,24&as_vis=1

Hoping you find some answers…

John