It’s Monday morning and I arrive early to get a cup of coffee before starting the new week. I quickly stop at my desk and the phone rings. I hear a familiar question, “Good morning, I want to ship some prunes to Japan. What will it cost me for pesticide testing?” I sit down; my coffee will have to wait because this is going to take some time. This conversation is all too familiar and I know in the end, the member will not be completely satisfied.
Simply put, pesticide residue testing is complicated. Customer requests seem simple: (1) test all pesticides known to mankind, (2) use high sensitivity and detection, (3) rapid turn-around time, (4) be relatively inexpensive and, (5) use an accredited laboratory that knows what they are doing.
Although these five requests don’t seem unmanageable, I would like to discuss the ease and discomforts that come with each step.
Test all pesticides: There are hundreds and hundreds of pesticides and each one is unique with its own challenge of detection. There are 649 registered “crop protection compounds” (also known as pesticides) with tolerances for food. Finding the ones that are approved for individual commodities and the tolerances is a challenge in itself. There are a number of online search engines but they all seem to miss some oddball compounds. Whenever asked to provide a list of “approved pesticides” in a commodity, I always balk, as the list changes on a regular basis and I may miss one myself. However, when asked if a specific pesticide is registered, I can easily locate the answer.
High Sensitivity and Detection: Pesticides can be volatile or not, water soluble or not, fluorescent or not, heat stable or not, plus a number of ‘other’ or not. Their individual chemical peculiarities affect how the laboratories detect and quantify them. Some are easy to detect at very low levels, but not all. As labs are required to get closer and closer to zero, detection and measuring becomes more and more difficult.
Rapid Turn Around Time: In pesticide testing there are three general screens that are used. Screen II was developed by the US FDA in Los Angeles by Milton Luke. The other two screens are the Carmabate Screen and the EBDC Screen (also known as the Ethylene bis-dithio carbamate screen). As you can image, each of the three screens have different strengths and weaknesses, so that’s why one screen may be better at detecting certain commodities and classifications of pesticides than another. All of these screens take time, especially when multiple pesticides are being tested individually. It’s important to ensure the pesticides are identified correctly. The turnaround time depends on the compounds you request. Most can be completed in a couple of days, some take up to a week. If outside analysis is required, it is not unusual for this to take a few weeks to complete.
Inexpensive: Everyone is concerned with laboratory expense. Cost is one of the most common questions a lab hears. Screen II, Carbamate Screen, EBDC Screen and some individual procedures can easily be over $900 per sample. This amount has never made anyone happy.
Accreditation of Laboratories: In California all laboratories in the pesticide business for food are required to be accredited by the Department of Health Services. If pesticide testing for food is done in other states, those labs are not required to have the rigorous requirements of California. ACFSQ/DFA has been accredited for more than a decade. The accreditation mandates an annual audit and incredibly difficult check samples. When the Japanese Ministry of Health Labor and Welfare evaluated our credentials, we were given an “Official Laboratory Status”. We are the only private lab in the United States with this recommendation.
As you can see, pesticides are very complicated. This is why I don’t have a simple answer when you call. Pesticides are complex and difficult, and the main reason my first cup of coffee comes at first break!
Staff Contact: Mike Hurley
